JP2007129196A - Electromagnetic field detection device, electromagnetic field detection sensor, electromagnetic detection circuit, magnetic recording reproducing head, information recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable highly efficient electromagnetic field detection using AB effect or AC effect under a normal temperature. <P>SOLUTION: The electromagnetic field detection device 10 has three stacked insulation layers 2, 3, 4. The breakdown field of the insulation layer 3 is larger than that of the insulation layers 2, 4. The three insulation layers 2, 3, 4 are held between a pair of electrodes 5, 6. The insulation layer 3 and the boundaries 7, 8 at opposite ends of the overlapping range of the opposing surfaces 5a, 6a of the electrodes 5, 6 in the Z direction are spaced apart, respectively, by the thicknesses t1, t3 of the insulation layers 2, 4. When an electric field causing breakdown of the insulation layers 2, 4, but not causing breakdown of the insulation layer 3 is applied between the pair of electrodes 5, 6; two ballistic current passages are formed between the pair of electrodes 5, 6 to hold the insulation layer 3 between. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used for recording / reproducing electromagnetic field information, an electromagnetic field detection element, an electromagnetic field detection sensor, an electromagnetic field detection circuit, and an electromagnetic field information used for detection of a minimal magnetic bit in high-density magnetic recording. The present invention relates to an information recording / reproducing head and an information recording / reproducing apparatus.

In recent years, the performance required for external information storage devices has increased dramatically due to the improvement of computing power and information communication ability of computers. In particular, demands for high-density recording exceeding 1 Tb / inch ² have begun to be made for hard disk drives. However, when the recording surface density is 1 Tb / inch ² , the size of the recording bit becomes extremely small, such as one bit size is about 25 nm square, and a conventional spin valve GMR (Giant Magneto Resistance) element or TMR (Tunnel) In the case of a Magneto Resistance element, it is expected that detection of recorded information will be difficult. Therefore, in order to achieve the required level of 1 Tb / inch ² , the appearance of an element based on a detection principle different from the conventional method is awaited.

  As a new detection principle different from the conventional method, there is an Aharanov-Bohm (AB) effect described in Non-Patent Document 1 below. As will be described in detail later, this effect is caused by the vector potential formed by the magnetic flux penetrating through the space between the two electron wave paths when the electron wave propagates while maintaining coherence. The phase difference of the electron wave is subject to change. Patent Document 1 listed below discloses a magnetic field detector using the coherence of electrons using the AB effect. Further, in the following Non-Patent Document 2, it is reported that the phase of an electron wave is changed by an electric field applied to the inside of a substance due to spin-orbit interaction in the substance even in the absence of a magnetic field (Aharanov-Casher (AC) effect ( For the detailed principle of this effect, see Non-Patent Document 3 below)). In the known magnetic detection element, it is necessary to detect a change in magnetoresistance after the magnetic field is transferred to the soft magnetic layer. On the other hand, an electromagnetic field detection element using the AB effect or the AC effect as a detection principle is detected. Since the object is not an electromagnetic field but a vector potential, the above-described transfer is unnecessary, and therefore, attenuation and delay associated with the transfer do not occur. Therefore, efficient electromagnetic field detection is possible, and there is an advantage that a minimal magnetic bit can be reproduced.

Japanese Patent Laid-Open No. 2-306412 Fukuyama Hidetoshi “New Development of Series Physical Physics Mesoscopic Physics” 55-57 Maruzen Publishing Division 1996 “NATURE VOL427” p. 50-53 January 2004 “Physical Review Letters Vol.53” p. 319-321 July 1984

  However, in the magnetic field detector of Patent Document 1, a semiconductor is used as an electron current path, and in order to realize an electron coherence effect (AB effect) in a magnetic field, a semiconductor that is a current path is made at a low temperature. To maintain the coherency of electrons. Therefore, at room temperature, the coherency of electrons in the semiconductor cannot be maintained, and magnetic field detection by the AB effect is impossible. In addition, the magnetic field detector disclosed in Patent Document 1 cannot realize an AC effect that is a coherent effect of electrons in an electric field at room temperature. The AC effect will be described in detail later.

  Accordingly, an object of the present invention is to provide an electromagnetic field detection element, an electromagnetic field detection sensor, an electromagnetic field detection circuit, and an electromagnetic field detection circuit that can detect an electromagnetic field using the AB effect or the AC effect at room temperature. An object of the present invention is to provide an information recording / reproducing head and an information recording / reproducing apparatus which are provided with a detecting element, an electromagnetic field detecting sensor, or an electromagnetic field detecting circuit and are used for recording / reproducing electromagnetic field information.

Means and effects for solving the problems

(1) The electromagnetic field detection element of the present invention includes a pair of counter electrodes arranged in an insulating region so as to have opposing surfaces facing each other, and an overlapping range of the opposing surfaces in one direction along the opposing surfaces. Is sandwiched between the pair of counter electrodes so as to be within the overlapping range while being spaced apart from both ends of the boundary, and more than the portion of the insulating region sandwiched between the pair of counter electrodes is dielectric breakdown. And a first insulator having a large electric field.

  According to the above configuration, when an electric field having a magnitude that does not cause dielectric breakdown of the first insulator is applied between the pair of counter electrodes while the dielectric region of the insulating region sandwiched between the pair of counter electrodes is applied, Two ballistic current paths are formed between which the first insulator is sandwiched. That is, two ballistic current paths are formed sandwiching the first insulator at room temperature. When an electromagnetic field exists in a region sandwiched between these two current paths or in the vicinity thereof, a ballistic (that is, coherent (coherent) that passes through the two current paths by a vector potential derived from the electromagnetic field. Phase change occurs in the carrier. As a result, the carriers that have passed through the two current paths cause interference due to mutual phase shift (AB effect for magnetic field and AC effect for electric field). In other words, since the electric conductivity between the counter electrodes changes due to the vector potential related to the external electromagnetic field, if the electrical characteristics of the electromagnetic field detection element are measured at room temperature, a static external electromagnetic field including an electromagnetic wave and a near field is generated. Can be detected. Further, by detecting an electromagnetic field change in a region sandwiched between two current paths or in the vicinity thereof as a change in electrical conductivity between the counter electrodes, dynamic external electromagnetic field detection at room temperature can be performed.

(2) The electromagnetic field detection element of the present invention is sandwiched between a pair of counter electrodes arranged in an insulating region so as to have opposing surfaces facing each other, and the pair of counter electrodes, and And a first insulator having a greater breakdown electric field than a portion sandwiched between the pair of counter electrodes in the region, and the sandwiched between the pair of counter electrodes in the insulating region When an electric field of a magnitude that does not cause dielectric breakdown of the first insulator while applying dielectric breakdown to the first insulator is applied between the pair of counter electrodes, the two insulators sandwiching the first insulator between the pair of counter electrodes A ballistic current path is formed.

  According to the above configuration, when an electromagnetic field is present in or near a region sandwiched between two ballistic current paths sandwiching the first insulator, it is formed at room temperature by a vector potential derived from the electromagnetic field. A phase change occurs in a ballistic carrier passing through two current paths. As a result, carriers that have passed through the two current paths cause interference due to mutual phase shift. In other words, since the electric conductivity between the counter electrodes changes due to the vector potential related to the external electromagnetic field, if the electrical characteristics of the electromagnetic field detection element are measured at room temperature, a static external electromagnetic field including an electromagnetic wave and a near field is generated. Can be detected. Further, by detecting an electromagnetic field change in a region sandwiched between two current paths or in the vicinity thereof as a change in electrical conductivity between the counter electrodes, dynamic external electromagnetic field detection at room temperature can be performed.

  As described above, the electromagnetic field detection elements (1) and (2) can perform high-efficiency electromagnetic field detection using the AB effect or the AC effect at room temperature. Moreover, the electromagnetic field detection element of the present invention has an advantage that the element structure is relatively simple and easy to manufacture.

  In (1) and (2), the insulating region is a solid, gas, or liquid as long as the portion sandwiched between the pair of counter electrodes has a smaller breakdown electric field than the first insulator. Either may be sufficient. For example, in the case of gas and liquid, the insulating region may or may not be part of the electromagnetic field detection element.

(3) The electromagnetic field detection element of the present invention is in contact with the first insulator while sandwiching the first insulator in the portion sandwiched between the pair of counter electrodes in the insulating region. The second and third insulators are preferably arranged. Thereby, by sandwiching the first insulator between two insulators in contact with the first insulator, the electric characteristics of the electromagnetic field detection element are stabilized, and external electromagnetic field detection with higher accuracy is possible.

(4) In the electromagnetic field detection element according to (3), the width of the second and third insulators in one direction along the facing surface is an electron in the conductive material constituting the pair of counter electrodes. Or less than the mean free path. Thereby, the coherence of the ballistic electron which reached | attained the electrode can be improved.

(5) In the electromagnetic field detection elements of (3) and (4) above, the second and third insulators are in contact with both of the two opposing surfaces of the pair of opposing electrodes. Is preferred. Thereby, the coherence of the ballistic carrier which reached the electrode can be enhanced.

(6) In the electromagnetic field detection elements of the above (3) to (5), it is preferable that the first to third insulators form a laminated structure having surfaces parallel to each other. As a result, the electromagnetic field can be detected in a minute region.

(7) In the electromagnetic field detection elements of the above (3) to (6), it is preferable that the facing surface is orthogonal to the surfaces of the first to third insulators. Thereby, the coherence of the ballistic carrier which reached the electrode can be enhanced.

(8) In the electromagnetic field detection elements of (3) to (7), it is preferable that at least one of the first to third insulators is made of a material having a magnetic permeability of 3 or more. Thereby, the detection efficiency of the external electromagnetic field can be improved by shifting the phase of the carrier passing through the current path by the magnetic field shift generated by the insulator made of the material having the magnetic permeability of 3 or more.

(9) Alternatively, in the electromagnetic field detection elements of the above (3) to (7), at least one of the first to third insulators is made of a material having a dielectric constant of 4 or more. May be. Thereby, the detection efficiency of the external electromagnetic field can be improved by shifting the phase of the carrier passing through the current path by the electric field shift generated by the insulator made of the material having a dielectric constant of 4 or more.

(10) In the electromagnetic field detection elements of the above (1) to (9), it is preferable that the shortest distance between the two opposing surfaces related to the pair of opposing electrodes is 100 nm or less. Thereby, the dielectric breakdown of the insulating region can be caused without increasing the voltage between the pair of counter electrodes.

(11) In the electromagnetic field detection elements of the above (1) to (10), the width of the first insulator in one direction along the facing surface is the conductive material constituting the pair of counter electrodes. It is preferably less than twice the mean free path of electrons. Thereby, the coherence of the ballistic carrier which reached the electrode can be enhanced.

(12) In the electromagnetic field detection element according to (11), the thickness of the first insulator in one direction along the opposing surface is an average of electrons in the conductive material constituting the pair of opposing electrodes. More preferably, it is less than the free stroke. Thereby, the coherence of the ballistic carrier that has reached the electrode can be further enhanced.

(13) In the electromagnetic field detection elements of (1) to (12), it is preferable that at least two step portions are formed on the facing surface. As a result, current concentration selectively occurs at the step portion when an electric field is applied, and ballistic carriers can be generated efficiently.

(14) In the electromagnetic field detection elements of the above (1) to (13), the first insulator is in contact with at least one of the two opposing surfaces related to the pair of opposing electrodes. Is preferred. Thereby, the coherence of the ballistic carrier which reached the electrode can be enhanced.

(15) An electromagnetic field detection sensor according to the present invention includes any one of the above-described (1) to (13), the two electromagnetic field detection elements formed between the pair of opposed electrodes in the electromagnetic field detection element. And a phase shift member that shifts the phase of the carrier that passes through at least one of the current paths. Thereby, the detection efficiency of the external electromagnetic field can be improved by shifting the phase of the carrier passing through the current path by a factor other than the external electromagnetic field.

(16) In the electromagnetic field detection sensor of (15), it is preferable that the phase shift member is a magnetic field generation source. Thereby, since the magnetic field generated by the magnetic field generation source changes the vector potential, the phase of the carrier passing through the current path can be shifted.

(17) Alternatively, in the electromagnetic field detection sensor according to (15), the phase shift member may be an electric field generation source. Thereby, the electric field generated by the electric field generation source changes the band structure in the material through the spin orbit interaction in the material in the first insulator and / or the insulating region, thereby changing the vector potential. Therefore, the phase of the carrier passing through the current path can be shifted.

(18) Alternatively, in the electromagnetic field detection sensor according to (15), the phase shift member may be an electromagnetic wave generation source. Accordingly, when the electromagnetic wave generated by the electromagnetic wave generation source causes carrier excitation and generation of electron-hole pairs in the first insulator and / or insulating region, the substance in the first insulator and / or insulating region The dielectric constant inside changes. Then, since the electric field in the first insulator and / or the insulating region changes, the phase of carriers passing through the current path can be shifted. By utilizing this, for example, the power of electromagnetic waves generated from a laser element can be monitored. In addition, when the electromagnetic wave generated by the electromagnetic wave generation source excites carriers in the insulating region to generate electron-hole pairs, the insulating region can be broken down at a low voltage.

(19) Alternatively, in the electromagnetic field detection sensor according to (15), the phase shift member may be a near-field generation source. Accordingly, when the near field generated by the near-field generation source causes carrier excitation in the first insulator and / or the insulating region and generation of electron-hole pairs associated therewith, the first insulator and / or the insulating region. The dielectric constant of the material in the region changes locally. Then, since the electric field in the first insulator and / or the insulating region changes, the phase of carriers passing through the current path can be shifted. By utilizing this, for example, the power of the near-field generating element can be monitored.

(20) An electromagnetic field detection circuit according to the present invention includes any one of the above-described (15) to (19) electromagnetic field detection sensors and a phase control circuit that controls a phase shift amount of a carrier by the phase shift member. I have. Thereby, the detection sensitivity of the electromagnetic field detection element can be maximized.

(21) The magnetic recording / reproducing head of the present invention includes an electromagnetic field generating element for recording electromagnetic field information on an information recording medium, and the above (1) to (14) for reading the electromagnetic field information recorded on the information recording medium. Any one electromagnetic field detection element is provided. Thereby, the electromagnetic field information recorded on the information recording medium by the electromagnetic field generating element can be detected with high sensitivity. Therefore, for example, a magnetic recording / reproducing head capable of recording and reproducing electromagnetic field information corresponding to a high recording surface density exceeding 1 Tb / inch ² is obtained.

(22) In the magnetic recording / reproducing head of (21), it is preferable that the electromagnetic field detecting element and the electromagnetic field generating element are integrally formed with a slider. As a result, it is possible to manufacture with a manufacturing process similar to that of the conventional magnetic head, so that productivity is improved. Further, since the terminals of the electromagnetic field detecting element and the electromagnetic field generating element are formed on the substrate integrated with the slider, the access of the terminals to the outside is facilitated and the productivity is improved.

(23) The information recording / reproducing apparatus according to the present invention includes any one of the above information recording / reproducing heads (21) or (22), and a moving unit that moves the information recording / reproducing head to a predetermined position on the information recording medium. And. Thereby, since the information recording / reproducing head can be moved to a predetermined position on the information recording medium, for example, electromagnetic field information in a nano-sized region corresponding to a high recording surface density exceeding 1 Tb / inch ² is recorded and recorded. Can be played.

<First Embodiment>
Hereinafter, an electromagnetic field detection element according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective configuration diagram of an electromagnetic field detection element according to the first embodiment of the present invention. FIG. 2 is a configuration diagram when the electromagnetic field detection element 10 of FIG. 1 is viewed from the Y-axis direction.

  As shown in FIG. 1, in the electromagnetic field detection element 10 according to the present embodiment, in order to detect an electromagnetic field in a minute region, insulating layers 2, 3, 4 have surfaces parallel to each other in order on the substrate 1. The electrodes 5 and 6 are formed so as to be in contact with the end surfaces in the interval L direction of the insulating layers 2, 3, and 4 and the surface of the substrate 1.

  The laminated portion composed of the insulating layers 2, 3, 4 is formed so as to be accommodated between the facing surfaces 5 a, 6 a of the electrodes 5, 6. In particular, in order to surely cause dielectric breakdown in the insulating layers 2 and 4, the insulating layer 3 is separated from the boundary surfaces 7 and 8 formed at both ends of the overlapping range of the opposing surfaces 5a and 6a in the Z-axis direction. However, it is sandwiched between the electrode 5 and the electrode 6 so as to be within the overlapping range of the facing surfaces 5a and 6a. The lower surface of the insulating layer 2 coincides with the boundary surface 8, and the upper surface of the insulating layer 4 coincides with the boundary surface 7. The facing surfaces 5a and 6a of the electrodes 5 and 6 are formed so as to be orthogonal to the surfaces of the insulating layers 2, 3 and 4. Thereby, the coherence of the ballistic carrier which reached the electrode can be enhanced.

  Further, an insulator or a semiconductor (not shown) having a high breakdown electric field is formed between the substrate 1 and the insulating layer 2 and the electrodes 5 and 6. Thereby, when an electric field is applied to the electrodes 5 and 6, it is possible to suppress the generation of ballistic electrons in the substrate 1 due to dielectric breakdown. This insulator or semiconductor is made of the same material as the substrate 1 or the insulating layers 2, 3, 4.

The insulating layer 3 is made of a material having a higher breakdown electric field than the insulating layers 2 and 4. As a result, when a voltage having a magnitude that does not cause the dielectric breakdown of the insulating layers 2 and 4 and does not cause the dielectric breakdown of the insulating layer 3 is applied between the opposing electrodes 5 and 6, it is formed between the opposing surfaces of the electrodes 5 and 6. In addition, along the interface between the insulator 3 having a large breakdown electric field and the surrounding insulating layers 2 and 4, dielectric breakdown selectively occurs, and ballistic carriers (here, electrons) accelerated by a high voltage are formed. Is done. Therefore, at least two ballistic current paths are formed between the opposing electrodes 5 and 6. The substrate 1 and the insulating layers 2, 3 and 4 are a group IV semiconductor such as Si, Ge and SiC, a group III-V compound semiconductor represented by GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb and AlN. II-VI compound semiconductors such as ZnTe, ZeSe, ZnS, and ZnO, oxide insulators such as ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ , and CeO ₂ , or nitride insulation such as SiN Consists of the body.

  The insulating layer 3 is made of a material having a magnetic permeability of 3 or more, such as ferrite or garnet. Therefore, the magnetic field shift generated by the insulating layer 3 shifts the phase of the carriers passing through the current path, so that the detection efficiency of the external electromagnetic field can be improved. Instead of the insulating layer 3, the insulating layer 2 or the insulating layer 4 may be formed of a material having a magnetic permeability of 3 or more.

  As a modification, the insulating layer 3 may be formed of a substance having a dielectric constant of 4 or more. According to this, since the electric field shift generated by the insulating layer 3 shifts the phase of the carriers passing through the current path, the detection efficiency of the external electromagnetic field can be improved. Instead of the insulating layer 3, the insulating layer 2 or the insulating layer 4 may be formed of a substance having a dielectric constant of 4 or more.

  As described above, the insulating layer 3 is made of a material having a higher breakdown electric field than the insulating layers 2 and 4. For example, when ZnO having a dielectric breakdown electric field of 1 MV / cm is formed on the insulating layers 2 and 4, the voltage required for the dielectric breakdown is 7V. ZnO can easily form oxygen vacancies and vacancies in the material by changing the film formation conditions (material composition, number of defects, amount of impurities, etc.), and can control (reduce) the breakdown electric field. . This can be applied to other oxide insulators and nitride insulators (in the case of nitride insulators, formation of nitrogen vacancies).

  The substrate 1 and the insulating layers 2, 3, 4 are preferably all semiconductors. This is because the semiconductor has a desired crystal growth, so that a flat insulating layer interface can be obtained at the atomic level and a linear current path can be obtained. In the case of using an oxide insulator or a nitride insulator, a film can be formed in the same manufacturing process, and the manufacturing cost can be reduced. It is desirable to use a nitride insulator. At this time, the substrate 1 may be any material as long as it is made of the above-described exemplary materials. Moreover, the insulating layers 2 and 4 do not need to be the same material.

Next, the layer thickness of the insulating layers 2, 3, and 4 will be described. As shown in FIG. 2, the thicknesses of the insulating layers 2, 3, and 4 are represented by t1, t2, and t3. By forming the insulating layers 2, 3, 4 and the counter electrodes 5, 6 as a multilayer structure on the substrate 1, a layer thickness t 2 that is also a distance between two penetrating paths of ballistic electrons by controlling the layer thickness of each layer and It is possible to control the layer thicknesses t1 and t3 which are also the penetration path widths. As a result, the region sandwiched between the two ballistic current paths can be limited to a size of several hundred nm ² , and the electromagnetic field can be detected in a nano-sized minute region. The layer thickness t2 of the insulating layer 3 is formed to be not more than twice (60 nm) the average free path (30 nm) of the metal electrons constituting the electrodes 5 and 6. Thereby, the coherence of ballistic electrons penetrating from the two paths is increased, and the detection sensitivity of the electromagnetic field is improved. In order to further improve the electromagnetic field detection sensitivity, the layer thickness t2 of the insulating layer 3 may be equal to or less than the mean free path (30 nm) of the metal electrons constituting the electrodes 5 and 6. In addition, the layer thicknesses t1 and t3 of the insulating layers 2 and 4 are formed to be equal to or less than the mean free path of the metal electrons constituting the electrodes 5 and 6, and the metal electrons constituting the electrodes 5 and 6 Compared with the case where the layer thickness is larger than the mean free path, the coherent property of the ballistic electron is improved.

  The electrodes 5 and 6 are arrange | positioned so that it may have opposing surface 5a, 5b inside, respectively. The material of the electrodes 5 and 6 may be a normal metal, but since a material having high electrical conductivity is preferable, Au, Ag, or Cu having an average free path of electrons in the metal of about 30 to 40 nm is used. Thereby, the coherency of the ballistic electron which reached the electrodes 5 and 6 can be improved. Although not shown, in order to improve the adhesion of the electrodes 5 and 6, between the insulating layers 2, 3, 4 and the electrodes 5 and 6, and between the substrate 1 and the electrodes 5 and 6, Zn An adhesion layer made of Ti, Cr, Al or the like is formed. The thickness of the adhesion layer is equal to or less than the mean free path (about 10 nm) of electrons in the metal constituting the adhesion layer in order to maintain the coherence of electrons. In addition, in order to increase the coherence of electrons in the two ballistic current paths between the opposed electrodes 5 and 6, the width W of the electrodes 5 and 6 is set so that the electrons of the metal used for the electrodes 5 and 6 It is below the mean free path.

The distance L between the electrodes 5 and 6 is 100 nm or less at the shortest portion. By shortening the distance between the electrodes 5 and 6 facing each other in this manner, dielectric breakdown can occur in the insulating layer 3 even at a low voltage, and ballistic electrons can be generated. More specifically, when the insulating layers 2 and 4 are formed of GaAs having an interval L of 70 nm and a dielectric breakdown electric field of 0.06 MV / cm, the voltage required for the dielectric breakdown = interval L (70 nm) × insulation The breakdown voltage (0.06 MV / cm) = 0.42V. When the insulating layers 2 and 4 are formed of 1 MV / cm ZnO, the voltage required for dielectric breakdown = interval L (70 nm) × dielectric breakdown voltage (1 MV / cm) = 7V. If the current based on space charge limited conduction is obtained, the voltage-current characteristic after dielectric breakdown is i∝V ² / L ³ from the child law. When the mobility of electrons in the insulating layers 2 and 4 is 30 cm ² / V · s, when the interval L is 100 nm, the applied voltage is 10 V, and the relaxation time of electrons in the insulating layers 2 and 4 is 1 ps, the electron velocity = Electron mobility × electric field, electric field = applied voltage / interval L From the equation, electron velocity = (30 cm ² / V · s) × (10 V / 100 nm) = 3 × 10 ⁷ m / s. Since the mean free path = electron velocity × electron relaxation time, the mean free path = (3 × 10 ⁷ m / s) × 1 ps = 300 nm. Although the mean free path is somewhat reduced depending on the reduction of the relaxation time due to defects in the insulators in the insulating layers 2 and 4 and the electric field distribution between the electrodes 5 and 6, the coherence is maintained at the interval L of 100 nm. Electrons can penetrate between the electrodes.

  Although not shown, the entire surface of the electromagnetic field detection element 10 is an insulator having a higher breakdown electric field than the insulating layers 2 and 4 in order to prevent a short circuit other than the insulating layers 2 and 4 between the electrodes 5 and 6. Covered with.

  Here, the operation of the electromagnetic field detection element 10 will be described together with the AB effect and the AC effect. FIG. 3 is a diagram used for explaining the principle of the AB effect.

(AB effect and operation of electromagnetic field detection element 10)
As shown in the upper diagram of FIG. 3, the electron beams e1 and e2 are emitted from the electron beam source 11, and the electron beams e1 and e2 pass through the gauge field in which the vector potential A due to the magnetic field B is generated. It is detected by the detector 12. In this case, the detected amount (conductivity) F of the electron beam oscillates periodically with respect to the magnetic field B. This is because the phases of the electron beams e1 and e2 change due to the vector potential A, and the electron beams e1 and e2 having different phases interfere with each other with the electron beam detector 12, so that the detection amount is as shown in the lower diagram of FIG. A periodic vibration of F appears. The vibration period (magnetic field [T]) is B ₀ = Φ ₀ / S. The flux quantum Φ ₀ = h / 2e is a universal constant of 2.07 × 10 ⁻¹⁵ [Wb], and S is an area surrounded by the paths of the electron beams e1 and e2. Here, when L = 70 nm and t2 = 30 nm and the path of the ballistic electron penetrates in the range of several nm near the interface of the insulating layer 3, S = (30 × 70) nm ² and the recording surface density is 300 Gb / inch ^2. The vibration period B ₀ [T] at this time is 0.98 [T]. When the bit size S corresponding to the recording surface density 1Tb / inch ² is S = (25 × 25) nm ² , the vibration period B ₀ [T] is 3.3 [T]. By subjecting the detection signal from the electromagnetic field detection element 10 to general signal processing, the magnetic field resolution can be increased to 1/1000 of the vibration period B ₀ . Accordingly, when the recording surface density corresponds to 1 Tb / inch ² , since the vibration period B ₀ = 3.3 [T], the magnetic field resolution is about 3 [mT]. Taking the magnetization 200 emu / cc of a typical magnetic recording medium of a hard disk as an example, the magnetic field generated from the magnetic recording medium is about 250 [mT] and can be sufficiently detected. Therefore, the electromagnetic field detection element 10 can sufficiently detect a leakage magnetic field from the magnetic recording medium even for a magnetic recording medium having a recording surface density exceeding 1 Tb / inch ² .

Here, as an example, an electromagnetic field detection element having substantially the same configuration as the electromagnetic field detection element 10 shown in FIG. 1 was actually manufactured, and the magnetoresistance effect of this electromagnetic field detection element was measured. First, a method for manufacturing the electromagnetic field detection element in this example will be described. A ZnO layer (thickness 30 nm), a SiO ₂ layer (thickness 40 nm), a ZnO layer (thickness 30 nm) on a Si substrate on which a thermal oxide film made of SiO ₂ is formed as a protective layer on the ZnO layer A SiO ₂ layer (thickness 100 nm) was sequentially formed by sputtering to form a multilayer structure. After the multilayer structure is formed, patterning with a resist is performed, and portions other than the portion covered with the resist by dry etching are cut to a depth of 250 nm to form layers corresponding to the insulating layers 2, 3, and 4. Thereafter, a Ti layer (thickness: 50 nm) as an adhesion layer and an Au layer (thickness: 200 nm) as electrodes are sequentially formed on the layers corresponding to the insulating layers 2, 3, and 4 by an electron beam evaporation method. The Ti layer and the Au layer on the substrate were removed by etching to produce an electromagnetic field detection element having substantially the same configuration as the electromagnetic field generation element 10. The interval L between the electrodes is 1 μm, and the electrode width W is also 1 μm.

  In the actually produced electromagnetic field detection element described above, when an IV curve was measured between the electrodes, good ohmic characteristics were obtained as shown in FIG. 21, and ballistic electrons could be generated even under a low voltage. In other words, since the electromagnetic field detection element shown in the experimental results shows ohmic characteristics, the resistance of the electromagnetic field detection element can be reduced and the impedance is lowered, so that the high frequency detection characteristic of the electromagnetic field detection element is improved and the consumption is reduced. Electricity can be realized.

  22 and 23 show the measurement results of the magnetoresistive effect of the actually produced electromagnetic field detection element described above when the applied voltage between the electrodes is 10V and 0.5V. 22 and 23, the vertical axis represents the current value, and the horizontal axis represents the magnetic field. The measurement was performed at room temperature (room temperature), and was measured with a semiconductor parameter analyzer using an external magnetic field generator and a Hall sensor.

As shown in FIG. 22 and FIG. 23, a magnetoresistance change of at least 10 ⁷ (7 digits) occurs when the magnitude of the magnetic field is around 0.2 T (2 kOe) and 0.25 T (2.5 kOe). It can be seen that an electromagnetic field detection element having a very large change is obtained. The magnitude of the externally applied magnetic field that causes a sudden change in magnetoresistance changes depending on the shape of the electrodes, the distance between the electrodes, and the change in the multilayer structure of the insulating layer. This is because it strongly depends on the coherency of ballistic electrons. Therefore, an electromagnetic field detection element having the same configuration as the above-described electromagnetic field detection element having a distance L between the electrodes and an electrode width W of 100 nm is considered to have the same effect as the electromagnetic field detection element in principle. It can be seen that by setting the distance L and the electrode width W to a size of 100 nm, the coherence of ballistic electrons is improved, and an electromagnetic field detection element capable of detecting an electromagnetic field with higher sensitivity can be realized.

電界Ｅを用いた場合、シュレーディンガー方程式は下記式（２）となる。

ここでのμは、電子の磁気モーメントのことである。電子の磁気モーメントはパウリ行列σにより、下記（３）式となる。なお、μ_Ｂは、ボーア磁子である。

ここで、電界Ｅと電子の磁気モーメント（スピン）によるスピン軌道相互作用をベクトルポテンシャルＡ_ＳＯの形式にみなせば、下記式（４）のようになる。

これは、電界Ｅによる位相変化について、形式的にＡＢ効果と同様に取り扱えることを意味する。つまり、電界Ｅと電子の磁気モーメントμからのベクトルポテンシャルＡ_ＳＯによって、電子の位相変化とその干渉効果とが生じることを示している。この効果をＡＣ効果と呼ぶ。この効果が発生すると、電子の２つの経路で印加される電界Ｅが異なることで、位相変化が現れる。この点がＡＢ効果と異なる点ではあるが、電気伝導度との関連は、ＡＢ効果の場合と同様である。 (AC effect and operation of electromagnetic field detection element 10)
The electromagnetic field detection element 10 can detect the spin orbit interaction in the electron path by the electron interference effect, and can detect the external electric field via the spin orbit interaction, so that the static external electric field can also be detected. Although this utilizes the AC effect, this AC effect will be described specifically comparing with the AB effect. In the AB effect, the magnetic field B is introduced as the vector potential A in the Schroedinger equation of the following formula (1).

When the electric field E is used, the Schroedinger equation becomes the following formula (2).

Here, μ is the magnetic moment of electrons. The magnetic moment of the electron is expressed by the following equation (3) according to the Pauli matrix σ. Note that μ _B is a Bohr magneton.

Here, it is regarded a spin-orbit interaction by the electric field E and the electron magnetic moment (spin) in the form of a vector potential A _SO, so the following equation (4).

This means that the phase change due to the electric field E can be treated formally in the same manner as the AB effect. In other words, the vector potential A _SO from the magnetic moments of the electric field E and the electron mu, shows that the electronic phase change and its interference effect occurs. This effect is called the AC effect. When this effect occurs, a phase change appears because the electric fields E applied in the two paths of electrons are different. Although this point is different from the AB effect, the relationship with electrical conductivity is the same as in the AB effect.

  In addition, the insulating layer 3 which is a region sandwiched between two electron beam paths absorbs an external electromagnetic wave (including a near field) to excite carriers and subsequently generate an electron / hole pair (described above). When the insulating layer 3 is irradiated with an external electromagnetic wave, the dielectric constant of the insulating layer 3 changes due to the generation of electron / hole pairs, thereby causing an internal electric field change. Such an electromagnetic field detection element 10 can detect this change in internal electric field as a change in vector potential, and thus can detect not only a static electromagnetic field but also a dynamic external electromagnetic wave.

  According to the electromagnetic field detection element 10 having the above-described configuration, the insulation layer 3 has a size that does not cause the dielectric breakdown of the insulation layer 3 while causing the dielectric breakdown of the portion sandwiched between the electrodes 5 and 6 in the insulation region composed of the insulation layers 2, 3, and 4. When an electric field is applied between the electrodes 5 and 6, two ballistic (ballistic) current paths are formed that sandwich the insulating layer 3 between the electrodes 5 and 6. That is, two ballistic current paths sandwiching the insulating layer 3 at room temperature are formed. When an electromagnetic field exists in a region sandwiched between these two current paths or in the vicinity thereof, a ballistic (that is, coherent (coherent) that passes through the two current paths by a vector potential derived from the electromagnetic field. Phase change occurs in the carrier. As a result, the carriers that have passed through the two current paths cause interference (AB effect or AC effect) due to mutual phase shift. That is, since the electrical conductivity between the electrodes 5 and 6 is changed by the vector potential related to the external electromagnetic field, if the electrical characteristics of the electromagnetic field detection element 10 are measured at room temperature, a static external including electromagnetic waves and near fields can be obtained. An electromagnetic field can be detected. In addition, by detecting the change in the electromagnetic field in the region sandwiched between the two current paths or in the vicinity thereof as the change in the electrical conductivity between the electrodes 5 and 6, it is possible to dynamically detect the external electromagnetic field at room temperature. Become. As described above, the electromagnetic field detection element 10 according to the present embodiment can perform highly efficient electromagnetic field detection using the AB effect or the AC effect at room temperature. Moreover, the electromagnetic field detection element 10 has an advantage that the element structure is relatively simple and easy to manufacture.

  Further, since the insulating layer 3 is sandwiched between the two insulating layers 2 and 4 that are in contact with the insulating layer 3, the electric characteristics of the electromagnetic field detecting element 10 are stabilized, and the external electromagnetic field can be detected with higher accuracy.

  In addition, since the insulating layers 2 and 4 are in contact with both the opposing surfaces 5a and 6a of the electrodes 5 and 6, it is possible to enhance the coherence of ballistic carriers that have reached the electrodes.

  Even if both end surfaces in the interval L direction of the insulating layers 2, 3, 4 are not in physical contact with the opposing surfaces 5 a, 6 a of the electrodes 5, 6, What is necessary is just to be close so that it may be formed. However, when both end faces in the interval L direction of the insulating layers 2, 3, 4 are in contact with the opposing faces 5 a, 6 a of the electrodes 5, 6, the coherency of the ballistic carrier that reaches the electrodes becomes higher. Further, when the dielectric breakdown electric field of the insulating layer 3 is larger than air, the insulating layers 2 and 4 may be removed. In that case, the air layers on both sides of the insulating layer 3 perform the same function as the insulating layers 2 and 4.

<Variation 1 of the first embodiment>
Next, Modification 1 of the first embodiment will be described. Note that parts similar to those in the first embodiment are denoted by the same reference numerals in the first place, and description thereof may be omitted. 4A and 4B are diagrams illustrating an electromagnetic field detection element according to Modification 1 of the first embodiment, in which FIG. 4A is a perspective configuration diagram and FIG. 4B is a top view. As shown in FIG. 4 (b), the electrodes 25 and 26 are connected across a portion of the insulating layer 22, 23, 24 and the width _{W 1,} the width is formed on the substrate 21 so is wider with distance from the center Yes. These points are different from the electromagnetic field detection element 10 of the first embodiment. Here, although the case where the widths of the connection portions of the electrodes 25 and 26 and the insulating layers 22, 23, and 24 are the same distance is shown, the widths may not be the same.

According to this modification, the same operation and effect as the electromagnetic field detection element 10 of the first embodiment can be obtained. Since it is easily possible to less than the mean free path of electrons in the width W ₁ electrodes 25 and 26, it is possible to enhance the coherence of the ballistic carriers reaching the electrodes 25 and 26.

<Modification 2 of the first embodiment>
Next, Modification 2 of the first embodiment will be described. Note that parts similar to those in the first embodiment are denoted by the same reference numerals in the first place, and description thereof may be omitted. FIG. 5 is a configuration diagram of the electromagnetic field detection element according to the second modification of the first embodiment when viewed from the Y-axis direction as in FIG. In the electromagnetic field detection element 30, the lengths of the insulating layers 32, 34 and the insulating layer 33 in the direction between the electrodes 35, 36 are different, and the lengths of the insulating layers 32, 34 are shorter than the insulating layer 33. Is formed. In other words, each of the opposing surfaces of the electrodes 35 and 36 is formed with one concave portion (in the drawing, reference numerals P1, Q1: P2, and Q2 are attached to boundary corners between the concave portion and the outside thereof), The interval P1-P2 and Q1-Q2 are the shortest part between the electrodes 35 and 36. These points are different from the electromagnetic field detection element 10 of the first embodiment.

  According to this modification, not only can the same operation and effect as the electromagnetic field detection element 10 of the first embodiment be obtained, but also when the electric field is applied between the electrodes 25 and 26, the shortest portion is selectively provided. There is also an effect that the electric field and current are concentrated and ballistic electrons are generated efficiently.

Second Embodiment
Next, an electromagnetic field detection circuit according to a second embodiment of the present invention will be described. Note that parts similar to those in the first embodiment are denoted by the same sign in the tenth place and the same place in the first place, and the description thereof may be omitted.

  FIG. 6 is a schematic diagram of an electromagnetic field detection circuit according to the second embodiment of the present invention. FIG. 7 is a perspective configuration diagram specifically showing the relationship between the electromagnetic field detection element and the magnetic field generation source of the electromagnetic field detection circuit of FIG. As shown in FIG. 6, the electromagnetic field detection circuit 100 according to the present embodiment includes an electromagnetic field detection sensor 101 and a phase control circuit 102.

  The electromagnetic field detection sensor 101 includes an electromagnetic field detection element 40, a fine metal wire 103 as a magnetic field generation source provided in the vicinity of the electromagnetic field detection element 40, and a reference resistor 104 connected in series to the electromagnetic field detection element 40. And a constant voltage power supply circuit 105 connected in series to the reference resistor 104 and a signal amplifier 106 connected in parallel to the reference resistor 104.

  As shown in FIG. 7, a thin metal wire 103 that generates a magnetic field B is disposed on the insulating layer 44 of the electromagnetic field detection element 40 (in the Z direction in FIG. 5). Although not shown, the fine metal wire 103 and the electrodes 45 and 46 are insulated through an insulator. The thin metal wire 103 is made of a material having high electrical conductivity (Au, Ag, or Cu). Further, the phase control circuit 102 can control the current i flowing through the thin metal wire 103. Here, the thin metal wire 103 is used as the magnetic field generation source. However, as another magnetic field generation source, for example, a magnetic coil or a magnetic material may be disposed.

  As shown in FIG. 7, when the thin metal wire 103 is disposed on the insulating layer 44, a magnetic field B is generated around the thin metal wire 103 by passing a current i through the thin metal wire 103, and the insulating layers 42, 43, A magnetic field B is applied to 44 substantially parallel to the Y-axis direction in FIG. The reason for this configuration is as follows. Usually, in addition to the desired electromagnetic field to be measured, the influence of the electric field generated at the interfaces of the insulating layers 42, 43, 44 and the electrodes 45, 46 of the electromagnetic field detection element 40, and the influence of the external leakage electromagnetic field This causes a phase change in the ballistic electrons. Therefore, in order to cancel this phase change, a metal thin wire 103 is newly provided as a magnetic field generation source, and the applied magnetic field B changes the phase of electrons penetrating the two insulating layers 42 and 44, thereby causing external factors. The detection efficiency of the external electromagnetic field is improved by controlling the phase shift due to a general factor.

  The metal thin wire 103 for phase shift control shown here is arranged so that the two electronic phase differences can be controlled in accordance with the phase shift due to an external factor.

  The reference resistor 104 detects the detection signal of the electromagnetic field detection element 40 as a voltage. The constant voltage power circuit 105 can apply a desired constant voltage to the electromagnetic field detection element 40. The signal amplifier 106 is used to amplify the detection signal.

  The phase control circuit 102 includes a lock-in detector 107, an output terminal 108, modulation signal transmitters 109 and 110, V / I converters 111 and 112, a switch 113, a hold circuit 114, and a switch circuit 115. And a resistor 116.

  The lock-in detector 107 can selectively detect a signal, and is connected in series with the signal amplifier 106 in the electromagnetic field detection sensor 101. The output terminal 108 is for outputting a detection signal, and is connected to the lock-in detector 107.

Modulation signal transmitter 109 is connected to the lock-in detector 107, it is intended to emit a signal of a frequency f _0. The V / I converter 111 converts a signal emitted from the modulation signal transmitter 110 emitted from the modulation signal transmitter 109 into a current. Similarly, the V / I converter 112 converts a signal into a current via a resistor 116. Further, these V / I converters 111 and 112 are connected to the thin metal wire 103 in the electromagnetic field detection sensor 101. The switch 113 is for turning on / off the electrical connection between the modulation signal transmitter 109 and the V / I converter 111.

The modulation signal transmitter 110 can generate a triangular wave signal having a frequency f ₁ lower than the frequency f ₀ toward the hold circuit 114. The hold circuit 114 can issue a hold signal to the switch circuit 115. The switch circuit 115 controls the modulation signal transmitter 110.

Next, the operation of the electromagnetic field detection circuit 100 will be described. First, a desired constant voltage is applied from the constant voltage power supply circuit 105 to the electromagnetic field detection element 40 via the reference resistor 104. At this time, the detection signal from the electromagnetic field detection element 40 is detected as the voltage of the reference resistor 104. This detection signal is amplified by the signal amplifier 106 and output to the output terminal 108 via the lock-in detector 107. When performing phase shift control, a phase control circuit 102 is used. Specifically, the switch 113 is turned on, the signal of the modulation signal transmitter 109 having the frequency f ₀ is converted into the current i by the V / I converter 111, the current i flows through the metal thin wire 103, and the modulation magnetic field B Is generated. The generated magnetic field B is detected by the electromagnetic field detection element 40, and the lock-in detector 107 performs signal amplification of the frequency f ₀ component of the detection signal generated from the electromagnetic field detection element 40. The amplified detection signal is input to the hold circuit 114, and the maximum value of the detection signal is monitored. Next, a triangular wave signal is input to the hold circuit 114 from the modulation signal transmitter 110 having a frequency f ₁ lower than the frequency f _0, and the input triangular wave signal is input to the V / I converter 112 via the resistor 116. Is converted into a current i. A current due to a signal from the lock-in detector 107 and a current corresponding to the triangular wave signal from the V / I converter 112 flow through the thin metal wire 103 in a superimposed manner. As a result, a magnetic field Bc is generated from the fine metal wire 103. The hold circuit 114 detects the phase of the triangular wave that maximizes the detection signal from the lock-in detector 107 within the period 1 / f ₁ and holds the voltage value of the phase. The switch circuit 115 turns off the modulation signal transmitter 110 according to the hold signal from the hold circuit 114. The hold signal from the hold circuit 114 is converted into a current i by the V / I converter 112, and a phase shift magnetic field B _p (a magnetic field when phase control is completed) corresponding to the hold signal is generated from the thin metal wire 103. This maximizes the detection sensitivity of the electromagnetic field generating element 40 when performing external electromagnetic field detection.

  According to the electromagnetic field detection circuit 100 of the present embodiment, since the magnetic field generated by the magnetic field generation source 103 changes the vector potential, the phase of the carrier passing through the current path can be shifted. As a result, the detection efficiency of the external electromagnetic field in the electromagnetic field detection element 40 can be improved. Furthermore, by using the phase control circuit 102, the detection sensitivity of the electromagnetic field detection element 40 can be maximized. This point will be described in detail with reference to FIG.

<Third Embodiment>
Next, an electromagnetic field detection circuit according to a third embodiment of the present invention will be described. Note that parts similar to those in the first embodiment are denoted by the same numeral in the tens place and having the same sign in the tens place, and description thereof may be omitted. Moreover, the site | parts with which code | symbol 201,202,204-210,213-216 in this embodiment are attached | subjected are the site | parts similar to the site | parts 101,102,104-110,113-116 of 2nd Embodiment. Therefore, the description of these may be omitted.

  FIG. 8 is a schematic diagram of an electromagnetic field detection circuit according to the third embodiment of the present invention. FIG. 9 is a perspective configuration diagram specifically showing the relationship between the electromagnetic field detection element and the electric field generation source of the electromagnetic field detection circuit of FIG. As shown in FIG. 8, the electromagnetic field detection circuit 200 according to the present embodiment includes an electromagnetic field detection sensor 201 and a phase control circuit 202.

  The electromagnetic field detection sensor 201 has substantially the same configuration as the electromagnetic field detection sensor 101 in the first embodiment, except that a metal plate 203 is used as an electric field generation source instead of the magnetic field generation source. Specifically, as shown in FIG. 9, a metal plate 203 which is an electric field generation source for generating an electric field E is disposed on the insulating layer 54 of the electromagnetic field detection element 50 (Z direction in FIG. 9). Yes. Although not shown, the metal plate 203 and the electrodes 55 and 56 are insulated via an insulator. The metal plate 203 is made of a material having high electrical conductivity (Au, Ag, or Cu). Further, the phase control circuit 202 can control the voltage V applied to the metal plate 203.

  As shown in FIG. 9, when the metal plate 203 is disposed on the insulating layer 54, an electric field E is generated around the metal plate 203 due to the voltage V applied to the metal plate 203, and the insulating layers 52 and 53. 54, the magnetic field E is applied substantially parallel to the Z-axis direction in FIG. The applied electric field E changes the band structure in the insulating layers 52, 53, and 54 through the spin orbit interaction in the insulating layers 52, 53, and 54, and this changes the vector potential. The reason for this configuration is as follows. Usually, in addition to the desired electromagnetic field to be measured, the influence of the electric field generated at the interfaces of the insulating layers 52, 53, 54 and the electrodes 55, 56 of the electromagnetic field detection element 50, and the influence of the external leakage electromagnetic field This causes a phase change in the ballistic electrons. Therefore, in order to cancel this phase change, a new metal plate 203 is provided, and the applied electric field E changes the phase of electrons penetrating through the two insulating layers 52 and 54, thereby preventing the external factors. By controlling the phase shift, the detection efficiency of the external electromagnetic field is improved.

  The metal plate 203 for phase shift control shown here is arranged so that two electronic phase differences can be controlled in accordance with the phase shift due to an external factor.

  The phase control circuit 202 has substantially the same configuration as the phase control circuit 102 in the first embodiment, but uses a voltage generation circuit 211 that applies a voltage V to the metal plate 203 instead of the V / I converters 111 and 112. Is different.

Next, the operation of the electromagnetic field detection circuit 200 will be described. First, a desired constant voltage is applied from the constant voltage power supply circuit 205 to the electromagnetic field detection element 50 via the reference resistor 204. At this time, the detection signal from the electromagnetic field detection element 50 is detected as the voltage of the reference resistor 204. This detection signal is amplified by the signal amplifier 206 and output to the output terminal 208 via the lock-in detector 207. When performing phase shift control, a phase control circuit 202 is used. Specifically, the switch 213 is turned on, the signal of the modulation signal transmitter 209 having the frequency f ₀ is converted into the voltage V by the voltage generation circuit 211, and the voltage V is applied to the electric field generation source 203. A modulation electric field E is generated. The generated electric field E is detected by the electromagnetic field detection element 50, and the lock-in detector 207 performs signal amplification of the frequency f ₀ component of the detection signal generated from the electromagnetic field detection element 40. The amplified detection signal is input to the hold circuit 214, and the maximum value of the detection signal is monitored. Next, a triangular wave signal is input to the hold circuit 214 from the modulation signal transmitter 210 having a frequency f ₁ lower than the frequency f _0, and the input triangular wave signal is converted into a voltage by the voltage generation circuit 211 via the resistor 216. Converted to V. A voltage V corresponding to a signal obtained by superimposing a signal from the lock-in detector 207 and a triangular wave signal from the hold circuit 214 is generated on the metal plate 203. As a result, an electric field E _c is generated from the metal plate 203. The hold circuit 214 detects the phase of the triangular wave that maximizes the detection signal from the lock-in detector 207 within the period 1 / f ₁ and holds the voltage value of the phase. The switch circuit 215 turns the modulation signal transmitter 210 off by the hold signal from the hold circuit 214. Hold signal from the hold circuit 214 is converted by the voltage generating circuit 211 to the voltage V, phase shift field E _p corresponding to the hold signal is generated from the metal plate 203. This maximizes the detection sensitivity of the electromagnetic field generating element 50 when performing external electromagnetic field detection.

  According to the electromagnetic field detection circuit 200 of the present embodiment, the electric field generated by the metal plate 203 changes the band structure in the material through the spin orbit interaction in the material in the insulating layer 53 and the insulating region, and the vector potential is changed. Since it is changed, the phase of the carrier passing through the current path can be shifted. As a result, the detection efficiency of the external electromagnetic field in the electromagnetic field detection element 50 can be improved. Furthermore, by using the phase control circuit 202, the detection sensitivity of the electromagnetic field detection element 50 can be maximized.

<Fourth embodiment>
Next, an electromagnetic field detection circuit according to a fourth embodiment of the present invention will be described. Note that parts similar to those in the first embodiment are denoted by the same sign in the tenth place and the same place in the tenth place, and the description thereof may be omitted. Moreover, since the site | parts with which the code | symbol 301,302,304-306 in this embodiment is attached | subjected are the site | parts similar to the site | part 101,102,104-106 of 2nd Embodiment, these are also the description. May be omitted.

  FIG. 10 is a schematic diagram of an electromagnetic field detection circuit according to the fourth embodiment of the present invention. FIG. 11 is a perspective configuration diagram specifically showing the relationship between the electromagnetic field detection element and the semiconductor laser element of the electromagnetic field detection circuit of FIG. As shown in FIG. 10, the electromagnetic field detection circuit 300 according to this embodiment includes an electromagnetic field detection sensor 301 and a phase control circuit 302.

  The electromagnetic field detection sensor 301 has substantially the same configuration as the electromagnetic field detection sensor 101 in the first embodiment, but instead of the magnetic field generation source, a semiconductor laser element 303 that is an electromagnetic wave generation source, a light detection element 317, and a laser The difference is that a drive circuit 318 and a laser drive current output circuit 319 are used.

  The semiconductor laser element 303 is connected to an input terminal 320 from a driving power source, and distributed Bragg reflectors 303a and 303b for realizing laser light oscillation are connected at both ends in the laser light oscillation direction (Y-axis direction in FIG. 11). A laser beam oscillating unit 303c in the vicinity of the electrodes, and electrodes 303d and 303e for injecting current into the laser beam oscillating unit 303c. As shown in FIG. 11, the laser light oscillation unit 303 c is configured so that the laser light oscillated from the active region 303 f of the semiconductor laser element 303 propagates to the insulating layers 62, 63, 64 of the electromagnetic field detection element 60. It is formed on the substrate 61 at a position sandwiched between two electrodes 65 and 66. The electrode 303d is formed on the substrate 61 along the laser light oscillation unit 303c near the side surface of the laser light oscillation unit 303c, and the electrode 303e is formed on the upper surface of the laser light oscillation unit 303c. Here, although not shown, the electromagnetic field detection element 60 and the semiconductor laser element 303 are coated with an insulator in order to maintain an insulating state with the electrodes 65 and 66 and the electrodes 303d and 303e. Instead of the distributed Bragg reflectors 303a and 303b, a reflective film may be formed on the cut-out end face (end face of the semiconductor laser element 303 when viewed from the Y-axis direction in FIG. 11).

  Such laser light oscillated from the semiconductor laser element 303 excites carriers in all or part of the insulating layers 62, 63, 64, and electron / hole pairs are generated. Accordingly, since the electron / hole pairs generate an electric field, the electric field to be applied to the electrodes 65 and 66 in order to break down the insulating layers 62 and 64 can be reduced. Further, the carrier excitation generated by the laser light oscillated from the semiconductor laser element 303 causes a change in dielectric constant in the whole or a part of the insulating layers 62, 63, 64, and the electric field inside the insulating layers 62, 63, 64 is changed. Since it changes, the phase of the ballistic electron changes according to the intensity of the laser beam and appears as a change in electrical mobility. Therefore, the power of the laser beam generated from the semiconductor laser element 303 can be monitored. The electronic phase can be controlled by the intensity of the laser beam.

  Since the parts 307 to 311 and 313 to 316 of the electromagnetic field detection sensor 301 have the same configuration as the parts 207 to 211 and 213 to 216 of the electromagnetic field detection sensor 201 in the second embodiment, explanation thereof Is omitted.

Next, the operation of the electromagnetic field detection circuit 300 will be described. First, a desired constant voltage is applied from the constant voltage power supply circuit 305 to the electromagnetic field detection element 60 via the reference resistor 304. At this time, the detection signal from the electromagnetic field detection element 60 is detected as the voltage of the reference resistor 304. This detection signal is amplified by the signal amplifier 306 and output to the output terminal 308 via the lock-in detector 307. When performing phase shift control, a phase control circuit 302 is used. Specifically, the switch 313 is turned on, the signal of the modulation signal transmitter 309 having the frequency f ₀ is converted into the voltage V by the voltage generation circuit 311, and this voltage V is input to the laser driving circuit 318. In accordance with the input voltage V, the laser drive current output circuit 319 causes a current to flow through the semiconductor laser element 303. Light emitted from the semiconductor laser element 303 is detected by the light detection element 317, and the laser power is converted as a current and input to the laser driving circuit 318. The laser drive circuit 318 is feedback-controlled from the current from the light detection element 317 so as to obtain a desired laser power corresponding to the potential V from the voltage generation circuit 311. For time t _s stabilization of the laser power is performed, the frequency f ₀ is adjusted to be sufficiently lower than 1 / t _s. Light emission from the semiconductor laser element 303 is detected by the electromagnetic field detection element 60, and the detection signal is amplified by a lock-in detector 307 with a frequency f ₀ component. The amplified detection signal is input to the hold circuit 314, and the maximum value of the detection signal is monitored. Next, a triangular wave signal is input to the hold circuit 314 from the modulation signal transmitter 310 having a frequency f ₁ lower than the frequency f _0, and the input triangular wave signal is supplied to the voltage generation circuit 311 via the resistor 316. Converted to V. Therefore, a voltage V corresponding to a signal obtained by superimposing the signal from the lock-in detector 307 and the triangular wave signal from the hold circuit 314 is applied to the semiconductor laser element 303. As a result, laser light is generated from the semiconductor laser element 303. The hold circuit 314 detects the phase of the triangular wave that maximizes the detection signal from the lock-in detector 307 within the period 1 / f ₁ and holds the voltage value of the phase. The switch circuit 315 turns off the modulation signal transmitter 310 by the hold signal from the hold circuit 314. The hold signal from the hold circuit 314 is converted into a voltage V by the voltage generation circuit 311, and phase shift laser light corresponding to the hold signal is generated from the semiconductor laser element 303. This maximizes the detection sensitivity of the electromagnetic field generating element 60 when performing external electromagnetic field detection.

  According to the electromagnetic field detection circuit 300 of the present embodiment, the laser light emitted from the semiconductor laser element 303 changes the vector potential, so that the phase of the carrier passing through the current path can be shifted. By utilizing this, the power of the laser beam generated from the semiconductor laser element 303 can be monitored. Further, when the laser light generated by the semiconductor laser element 303 excites carriers in the insulating region and electron-hole pairs are generated, the insulating region can be broken down at a low voltage. As a result, the detection efficiency of the external electromagnetic field in the electromagnetic field detection element 60 can be improved. Furthermore, by using the phase control circuit 302, the detection sensitivity of the electromagnetic field detection element 60 can be maximized.

<Modification 1 of 4th Embodiment>
Here, Modification 1 of the fourth embodiment will be described. Here, a case where the laser power control of the semiconductor laser element and the phase control associated with the laser light detection are performed using the detection signal of the electromagnetic field detection element without using the light detection element will be described. Note that parts similar to those in the first embodiment are denoted by the same numeral in the tens place as 7 and the same place in the first place, and the description thereof may be omitted. Moreover, since the site | parts with which the code | symbol 401, 402, 404-406 in this embodiment is attached | subjected are the site | parts similar to the site | part 101,102,104-106 of 2nd Embodiment, these also demonstrate the description. May be omitted. FIG. 12 is a schematic diagram of an electromagnetic field detection circuit according to a modification of the fourth embodiment of the present invention. An electromagnetic field detection circuit 400 according to this modification includes an electromagnetic field detection sensor 401 and a phase control circuit 402.

  The electromagnetic field detection sensor 401 has substantially the same configuration as the electromagnetic field detection sensor 301 in the fourth embodiment, but is different in that the light detection element 317 is not used.

  The phase control circuit 402 has substantially the same configuration as the phase control circuit 302 in the fourth embodiment, except that a hold circuit 414 and a laser drive circuit 318 are directly connected. Although not shown, the phase control circuit described in the second or third embodiment exists, and the electromagnetic field is detected by the phase control circuit described in the second or third embodiment before the detection of the laser beam. The difference is that phase control has already been performed so that the detection sensitivity of the generating element 70 is maximized. In addition, since each site | part of 407-411, 413-416 of the electromagnetic field detection sensor 401 is the same structure as each site | part 207-211, 213-216 of the electromagnetic field detection sensor 201 in 2nd Embodiment, The description is omitted.

  Next, laser power control of the semiconductor laser element 403 will be described. First, a desired constant voltage is applied from the constant voltage power supply circuit 405 to the electromagnetic field detection element 70 via the reference resistor 404. At this time, the detection signal from the electromagnetic field detection element 70 is detected as the voltage of the reference resistor 404. This detection signal is amplified by the signal amplifier 406 and output to the output terminal 408 via the lock-in detector 407. A voltage V corresponding to the desired laser power is input to the laser drive circuit 418 from the input terminal 421. In accordance with the input voltage V, the laser drive current output circuit 419 causes a current to flow through the semiconductor laser element 403 connected to the input terminal 420 of the drive power supply. Light emission from the semiconductor laser element 403 is detected by the electromagnetic field detection element 70, and the detection signal is converted into a desired voltage V by the voltage generation circuit 411 via the hold circuit 414, and the voltage V is converted into the laser drive circuit 418. Is input. At this time, the laser drive circuit 418 outputs a signal to the hold circuit 414 so that the detection signal from the electromagnetic field detection element 70 is directly sent to the laser drive circuit 418 by the signal. In the laser drive circuit 418, a signal indicating a deviation is calculated from the signal from the input terminal 421 and the detection signal from the electromagnetic field detection element 70, and after the deviation signal is amplified, the amplified signal is converted into a laser drive current output circuit. Feedback is performed so that the set laser power corresponding to the signal from the input terminal 421 is input. After the control of the laser power is completed, the laser drive circuit 418 stops the signal to the hold circuit 414. With the above procedure, laser power control capable of outputting a desired laser power is realized using the electromagnetic field detection element 70.

When performing phase shift control after laser power control, a phase control circuit 402 is used. Specifically, the switch 413 is turned on, the signal of the modulation signal transmitter 409 having the frequency f ₀ is converted into a desired voltage V by the voltage generation circuit 411, and this voltage V is input to the laser drive circuit 418. . In accordance with the input voltage V, the laser drive current output circuit 419 causes a current to flow through the semiconductor laser element 403. Here, a laser beam is oscillated by passing a current modulated to a value larger than the threshold current of the semiconductor laser element 403 through the semiconductor laser element 403. Light emitted from the semiconductor laser element 403 is detected by the electromagnetic field detection element 70, and the laser power is converted as a current and input to the laser driving circuit 418. The laser driving circuit 418 is feedback-controlled so as to obtain a desired laser power from a signal from the light detection element 417. For time t _s stabilization of the laser power is performed, the frequency f ₀ is adjusted to be sufficiently lower than 1 / t _s. The electromagnetic field detection element 70 detects light emitted from the semiconductor laser element 403, and the detection signal is amplified by a lock-in detector 407 with a frequency f ₀ component. The amplified detection signal is input to the hold circuit 414, and the maximum value of the detection signal is monitored. Next, a triangular wave signal is input to the hold circuit 414 from the modulation signal transmitter 410 having a frequency f ₁ lower than the frequency f _0, and the input triangular wave signal is supplied to the voltage generation circuit 411 via the resistor 416. Converted to V. Therefore, a voltage V corresponding to a signal obtained by superimposing a signal from the lock-in detector 407 and a triangular wave signal from the hold circuit 414 is applied to the semiconductor laser element 403. As a result, laser light is generated from the semiconductor laser element 403. The hold circuit 414 detects the phase of the triangular wave that maximizes the detection signal from the lock-in detector 407 within the period 1 / f ₁ and holds the voltage value of the phase. The switch circuit 415 turns off the modulation signal transmitter 410 according to the hold signal from the hold circuit 414. The hold signal from the hold circuit 414 is converted into a voltage V by the voltage generation circuit 411, and phase shift laser light corresponding to the hold signal is generated from the semiconductor laser element 403. This maximizes the detection sensitivity of the electromagnetic field generating element 70 when performing external electromagnetic field detection.

  According to this modification, the laser light emitted from the semiconductor laser element 403 changes the vector potential, so that the phase of carriers passing through the current path can be shifted. As a result, the detection efficiency of the external electromagnetic field in the electromagnetic field detection element 70 can be improved. Further, by using the phase control circuit 402, the detection sensitivity of the electromagnetic field detection element 70 can be maximized. Furthermore, since no photodetection element is used, the configuration can be simplified compared to the electromagnetic field detection circuit 300 of the fourth embodiment.

<Fifth Embodiment>
Next, a magnetic recording / reproducing head according to a fifth embodiment of the invention will be described. Note that parts similar to those in the first embodiment may be given the same sign in the tenth place and the same place in the tenth place, and the description thereof may be omitted.

  FIG. 13 is a front structural view showing a magnetic recording / reproducing head according to the fifth embodiment of the present invention. As shown in FIG. 13, a magnetic recording / reproducing head 500 includes an electromagnetic field generating element 501 formed on a substrate 81 and an electromagnetic field detecting element formed on the electromagnetic field generating element 501 through an insulating layer 502. 80.

  The electromagnetic field generating element 501 includes a pair of electrodes 504 and 505 formed so as to sandwich the insulator 503, a thin conductor layer 506 formed so as to straddle the electrodes 504 and 505, and a Y-axis direction on the substrate 81 And a semiconductor laser element having the same configuration (not shown in FIG. 13 because it is the back side of each element). The electromagnetic field detection element 80 includes insulating layers 82, 83, 84 and electrodes 85, 86.

  The electrodes 504 and 505 and the conductor layer 506 are made of a metal or carbon nanotube with high electrical conductivity. In particular, when considering high-frequency response, nonmagnetic metals such as Au, Pt, Ag, Cu, Al, Ti, W, Ir, and Pd are used. Although not shown, the interfaces between the electrodes 504 and 505 and the conductor layer 506 and the interfaces between the electrodes 504 and 505 and the conductor layer 506 and other insulator parts are made of Zn, Ti, Cr, Al, or the like. An adhesion layer is formed.

A _w, A _h in FIG. 13 shows the width and height of the active region of the semiconductor laser element (not shown), the laser beam is configured to propagate in a region surrounded by a dotted line. There is a gap G between the electrodes 504 and 505, and the gap G is filled with a transparent insulator 503. G is 200 nm or less, and the width of the conductor layer 506 (the Y-axis direction length in FIG. 13) is 400 nm or less. When the conductor layer 506 is made of Au, the cross-sectional area (cut surface perpendicular to the X axis) of the conductor layer 506 is formed to be larger than about 6400 nm ² . This is because if the cross-sectional area is smaller than 6400 nm ² , the conductor layer 506 is heated and melted by Joule heat generated when the current i flows. For other conductive materials, the cross-sectional area is equal to or larger than that of Au.

  Next, the principle of electromagnetic field generation by the electromagnetic field generating element 501 will be described with reference to FIG. 14, and the operation of the electromagnetic field detecting element 80 will also be described. When a current i flows from the electrode 505 to the electrode 504 through the conductor layer 506, a magnetic field B is generated at a portion corresponding to the gap G of the conductor layer 506. In addition, when the potential V is applied to the conductor layer 506, an electric field is generated around the conductor layer 506. Further, when laser light is irradiated from the semiconductor laser element, a near field NF is generated at a portion corresponding to the gap G of the conductor layer 506. Here, the principle of generation of the near field will be described. When an electromagnetic wave (in the near infrared to visible light region) is irradiated to the interface between the metal (here, the conductive layer 506) and the dielectric substance (here, the insulating layers 502 and 503), the charge in the metal is applied to the interface. The sparse / dense wave is generated and coupled with the irradiated electromagnetic wave. In this state, electromagnetic waves are confined in the interface and cannot propagate in a direction perpendicular to the interface. Such a state is called a state where a near field is generated. The near field here is a general term for evanescent waves, surface plasmons, surface plasmon polaritons, local surface plasmon polaritons, and the like. Therefore, the phase difference between the two ballistic electrons in the electromagnetic field detecting element 80 can be controlled by the magnetic field B, the electric field E, and the near field NF from the electromagnetic field generating element 501. In the electromagnetic field detection element 80, similarly to the carrier excitation in the insulating layers 82, 83, and 84 by laser light, the insulating layers 82, 83, and 84 are also generated by the near-field NF due to the generation of electron / hole pairs accompanying the carrier excitation. As a result, the phase of the ballistic electrons changes and appears as a change in electrical conductivity. Therefore, the power of the near field NF generated from the electromagnetic field generation element 501 can be monitored by the electromagnetic field detection element 80. In addition, any one of the insulating layers 82, 83, and 84 may be irradiated with the laser beam. If the insulating layer 503 is made of a transparent material, near-field attenuation at the interface between the insulating layer 503 and the conductive layer 506 made of a metal material can be suppressed.

According to the present embodiment, the electromagnetic field information recorded on the information recording medium by the electromagnetic field generating element 501 can be detected by the electromagnetic field detecting element 80 with high sensitivity. Therefore, for example, a magnetic recording / reproducing head 500 capable of recording and reproducing electromagnetic field information corresponding to a high recording surface density exceeding 1 Tb / inch ² is obtained. Further, by using the electromagnetic field generating element 501, the phase of the electromagnetic field detecting element 80 can be controlled by the electric field E, the magnetic field B, and the near field NF generated from the electromagnetic field generating element 501. The detection sensitivity of the electric field E, the magnetic field B, and the near field NF is improved.

  Note that the phase control in this embodiment can be realized by using or combining the phase control circuits described in the second to fourth embodiments.

<Modification of Fifth Embodiment>
Next, a magnetic recording / reproducing head according to a modification of the fifth embodiment will be described. It should be noted that parts similar to those of the first embodiment may be given the same sign in the tenth place and the same place in the tenth place, and the description thereof may be omitted.

  FIG. 15 is a front structural view showing a magnetic recording / reproducing head according to a modification of the fifth embodiment of the present invention. As shown in FIG. 15, the magnetic recording / reproducing head 600 includes an electromagnetic field detecting element 90 formed on a substrate 91 and an electromagnetic field generating element formed on the electromagnetic field detecting element 90 via an insulating layer 602. 601.

  The electromagnetic field detection element 90 includes insulating layers 92, 83, 84 formed on the substrate 91 and electrodes 85, 86. The electromagnetic field generating element 601 includes a conductor layer 606 formed on the insulating layer 602, electrodes 604 and 605 formed on the conductor layer 606 and the insulating layer 602 so as to sandwich the insulator 603, and a substrate 91. The semiconductor laser device (not shown in FIG. 15 because it is the back side of each device) having the same configuration as that of the fourth embodiment is provided in the Y-axis direction.

  If it is the said structure, while being able to obtain the effect | action and effect similar to 5th Embodiment, since the electromagnetic field detection element 90 can be formed using a crystal substrate for the board | substrate 91, the insulating layers 92 and 93 In the case where each of the layers 94 and 94 is made of a crystalline material, the crystallinity can be improved to increase the dielectric breakdown electric field and to improve the electron conductivity.

<Sixth Embodiment>
Next, an information recording / reproducing apparatus according to a sixth embodiment of the present invention will be described. FIG. 16 is a perspective view showing the configuration of the main part of an information recording / reproducing apparatus according to the sixth embodiment of the present invention. FIG. 17 is an enlarged perspective view of the vicinity of the information recording / reproducing head of the information recording / reproducing apparatus shown in FIG. FIG. 18 is a diagram for explaining the operation of recording / reproducing electromagnetic field information performed on the information recording medium by the information recording / reproducing head of the information recording / reproducing apparatus shown in FIG.

  The information recording / reproducing apparatus 700 includes an arm 702 that is moved by an actuator 701 that is a moving unit, a slider 703 that is supported by the arm 702, an information recording / reproducing head 800 that is attached to the slider 703, and an information recording / reproducing head 800. And an information recording medium 704 on which electromagnetic field information is recorded / reproduced.

  As shown in FIGS. 17 and 18, the information recording / reproducing head 800 has the same configuration as the information recording / reproducing head 500 in the fifth embodiment, and includes a semiconductor laser element 802 and an electromagnetic field formed on a substrate 806. A generation element 803 and an electromagnetic field detection element 804 formed on the electromagnetic field generation element 803 via an insulating layer 805 are provided. The electrodes 803a and 803b of the electromagnetic field generation element 803, the electrodes 802a and 802b of the semiconductor laser element 802, and the electrodes 804a and 804b of the electromagnetic field detection element 804 that are electrically connected via the conductive layer 803c are flexible. The thin wire of the cable is connected. The electromagnetic field detection element 804 has insulating layers 804c, 804d, and 804e having the same configuration as the information recording / reproducing head 500 in the fifth embodiment.

  As shown in FIG. 17, an air bearing structure 801 is formed below the slider 703, and slides on the recording surface 704a of the rotating information recording medium 704. The distance (flying height) between the information recording / reproducing head 800 and the recording surface 704a is set to 100 nm or less. The slider 703 scans a recording track of the information recording medium 704 by an actuator 701 which is a moving unit.

  The information recording medium 704 is a general magnetic recording medium used in a hard disk drive, such as a CoCrPt magnetic recording medium, a rare earth transition metal magnetic recording medium, or an FePt magnetic recording medium. Alternatively, it may be a magnetic recording medium made of an antiferromagnetic material such as RhFe. Alternatively, it may be a medium that causes a phase change due to heat.

  Next, an operation principle of recording or reproducing the information recording / reproducing head 800 of the present embodiment with respect to the information recording medium 704 will be described with reference to FIG.

  First, the operation principle during recording will be described. As described in the fifth embodiment, laser light is emitted from the semiconductor laser element 802 of the information recording / reproducing head 800 to the conductor layer 803c of the electromagnetic field generating element 803 to generate a near field around the gap. The information recording medium 704 is locally heated by the generated near field. When the information recording medium 704 is made of a magnetic material having a large coercive force, the coercive force decreases at the locally heated portion of the information recording medium 704. At the same time, by applying a current i to the conductor layer 803c and applying a magnetic field B greater than the coercive force of the information recording medium 704, near-field assisted magnetic recording is performed. In FIG. 18, when the information recording medium 704 moves relative to the electromagnetic field generating element 803 toward the left side of the drawing, near-field assisted perpendicular magnetic recording is performed. Conversely, when the information recording medium 704 moves toward the right side of the drawing with respect to the electromagnetic field generating element 803, near-field assisted oblique magnetic recording is performed. If the generated magnetic field is stronger than the coercive force of the information recording medium 704 at normal temperature, normal magnetic recording may be performed. When the information recording medium 704 is composed of a phase change medium, phase change recording is performed by local heating of the information recording medium 704 due to generation of a near field. As described above, recording on the information recording medium 704 is realized by the electromagnetic field generating element 803.

Next, the operation principle during reproduction will be described. A desired high electric field is applied to the electromagnetic field detection element 804 to generate two ballistic electron paths. FIG. 19 is a diagram for explaining the state of electromagnetic field detection when the magnetic recording bit 704c recorded on the information recording track 704b of the information recording medium 704 shown in FIG. 18 passes near the electromagnetic field detection element 804. It is. In FIG. 19, a perpendicular magnetic recording medium will be described as an example. In the information recording track 704b, magnetic recording bits 704c perpendicular to the paper surface of FIG. 19 and having anti-parallel magnetization directions are alternately arranged. The vector potential by the magnetic recording bit 704c is indicated by a dotted arrow. In the uppermost magnetic recording bit 704c, the magnetization is directed toward the paper surface, and a counterclockwise vector potential is formed. When the traveling direction of the path e1 of the ballistic electron is opposite to the vector potential and the traveling direction of the path e2 is the same direction as the vector potential as shown in the left diagram of FIG. 19A, the phase changes between the two ballistic electrons. Occurs. The phase difference between the two ballistic electrons is 2πΔΦ / Φ ₀ . Here, Φ ₀ is a magnetic flux quantum, and ΔΦ is a magnetic flux amount in a region sandwiched between two ballistic electron paths. At this time, the electric conductivity F of the electromagnetic field detection element 800 decreases by the phase difference (center diagram in FIG. 19A).

  As shown in the left diagram of FIG. 19B, when both the traveling directions of the ballistic electron paths e1 and e2 are orthogonal to the vector potential, no phase change occurs between the two ballistic electrons. Therefore, the electrical conductivity F of the electromagnetic field detection element 800 does not decrease (center diagram in FIG. 19B).

When the traveling direction of the path e1 of the ballistic electron is in the same direction as the vector potential and the traveling direction of the path e2 is opposite to the vector potential as shown in the left diagram of FIG. 19C, the phase change between the two ballistic electrons. Occurs. The phase difference between the two ballistic electrons is −2πΔΦ / Φ ₀ contrary to the case of FIG. The amount of magnetic flux in a region sandwiched between two ballistic electron paths is −ΔΦ. At this time, the electric conductivity F of the electromagnetic field detection element 800 is decreased by the same amount as in FIG. 19A (center of FIG. 19C). However, since the amount of magnetic flux Φ, that is, the phase difference is different between the two, the direction of change is reversed between the central view of FIG. 19A and the central view of FIG. 19C.

  Here, by changing the external magnetic field B, the electric field E, the magnetic permeability μ and the dielectric constant ε of the insulating layer 804d and introducing the same phase shift between the two ballistic electrons, the amount of magnetic flux is set to Φ + θ. . θ (B, E, μ, ε) is a function of the magnetic field B, the electric field E, the magnetic permeability μ, and the dielectric constant ε. For example, the electromagnetic field detection sensitivity of the electromagnetic field detection element 804 can be maximized by performing phase control using a phase control circuit as shown in FIG. 6, FIG. 8, FIG. 10, or FIG. Before phase control, as can be seen by comparing the central views of FIGS. 19A, 19B, and 19C, the difference in electrical conductivity F between them is relatively small. As can be seen by comparing the center diagram of A) with the center diagram of FIG. 19C, these two electrical conductivities F are the same. On the other hand, when the magnetic flux amount is Φ + θ, when θ> 0, reproduction is performed in the opposite phase to that of the magnetic recording bit (with the polarity (positive / negative) of the polarity (positive / negative) of the magnetic recording bit signal reversed) ) And the detection sensitivity is maximized when θ = π / 2. That is, as can be seen by comparing the right diagrams of FIGS. 19A, 19B, and 19C, the difference between the electrical conductivities F is relatively large, and the right side of FIG. As can be seen by comparing the figure with the right figure in FIG. 19C, the difference between these two electrical conductivities F is the maximum value. Therefore, by monitoring the electrical conductivity at this time, it is possible to detect the magnetic recording bit with high accuracy by detecting information on the magnetic recording bit. Similarly, when θ <0, reproduction is performed in the same phase as the magnetic recording bit, and the detection sensitivity is maximized when θ = −π / 2.

Although the magnetic recording is taken up here, the electromagnetic field detecting element 804 can detect an electric field and a near field other than the magnetic field in principle because it directly detects the vector potential. Therefore, when the information recording medium 704 is composed of a phase change recording medium, the electric field E of the magnetic recording bit 704c of the phase change recording medium is detected, and the near field generated from the electromagnetic field generating element 803 is reflected by the magnetic recording bit 704c. The near field can be detected by the electromagnetic field detection element 804. Regarding the arrangement of the electromagnetic field detection element 804 and the information recording track 704b, detection is possible even if they are arranged at an arbitrary angle. From the above, if the size of the region sandwiched between two ballistic electron paths is set to a size of 25 nm square, the electromagnetic field information corresponding to the recording surface density exceeding 1 Tb / inch ² can be detected. Alternatively, an information recording / reproducing head for performing reproduction can be provided.

  Next, the operation of the information recording / reproducing apparatus 700 will be described. FIG. 20 is a schematic block diagram for explaining the recording / reproducing operation of the information recording / reproducing apparatus 700.

  The information recording / reproducing apparatus 700 further includes a recording / reproducing control terminal 901 for controlling recording or reproduction from the upper apparatus, an input terminal 902 for inputting recording data from the upper apparatus, and an output terminal 903 for outputting reproduced data to the upper apparatus. have. Also connected to a recording / reproduction control terminal 901, a recording / reproduction control unit 904 for controlling recording or reproduction, an input terminal 902, a data recording unit 905 for converting recording data into a recording signal, and an output terminal 903. And a data reproduction unit 906 that encodes the reproduction signal. Further, a laser emission unit 907 including a semiconductor laser element 802, a laser driving unit 908, an electromagnetic field generation unit 909 including an electromagnetic field generation element 803, a current / voltage control unit 910, and an electromagnetic field detection element And an electromagnetic field detection unit 911 provided with 804.

  The recording / reproducing control unit 904 generates a recording magnetic field in accordance with a recording signal from the data recording unit 905, the data reproducing unit 906, a laser driving unit 908 that controls the laser driving current of the laser emitting unit 907, and the recording signal from the data recording unit 905. It is connected to a current / voltage control unit 910 that controls the current flowing to the unit 909. The electromagnetic field detection unit 911 receives the laser beam from the laser emission unit 907 or the near field generated from the electromagnetic field generation unit 909 according to an instruction from the recording / reproduction control unit 904, and applies the laser beam intensity to the recording / reproduction control unit 904. Is output to the recording / reproducing control unit 904, and the recording / reproducing control unit 904 controls the laser driving unit 908 so that the near-field generated from the laser light intensity or electromagnetic field generating unit 909 is constant. The electromagnetic field detection unit 911 detects a change in intensity due to the interaction between the information recording medium 704 and the near field generated from the electromagnetic field generation unit 909, and outputs the detection result to the data reproduction unit 906.

  In the case of normal magnetic recording, the current / voltage control unit 910 supplies a current corresponding to the recording data to the electromagnetic field generation unit 909 according to a recording signal from the data recording unit 905 and an instruction from the recording / reproducing control unit 904. generate. Thereby, information recording is performed on the information recording medium 704. In the case of near-field assisted magnetic recording, in addition to the procedure for normal magnetic recording, the laser drive unit 908 is controlled by an instruction from the recording / reproducing control unit 904, and the laser light emitting unit 907 generates laser light of a desired intensity. Then, when the near field is generated in the electromagnetic field generating unit 909, the information recording medium 704 is locally heated, and near field assisted magnetic recording is realized only in the overheated area, and information recording is performed. In the case of phase change recording by the near-field NF, the recording / reproducing control unit 904 issues an instruction to the laser driving unit 908 from the recording signal from the data recording unit 905, and the laser emitting unit 907 generates laser light with a desired intensity. When the near field is generated in the electromagnetic field generation unit 909, the information recording medium 704 is locally heated, and phase change recording is performed only in the overheated region.

  As a previous stage of reproduction, in order to maximize the detection sensitivity of the electromagnetic field, a desired phase shift is performed on the ballistic electrons in the electromagnetic field detection unit 911 using the above-described phase control circuit. During reproduction, a desired magnetic field or electric field, or near field is generated from the electromagnetic field generation unit 909 according to an instruction from the recording / reproduction control unit 904. The electromagnetic field detection unit 911 detects the electromagnetic field information from the recording mark of the information recording medium 704 and outputs a reproduction signal to the data reproduction unit 906. In response to an instruction from the recording / playback control unit 904, the data playback unit 906 converts the playback signal into playback data and outputs the playback data to the output terminal 903.

According to this embodiment, the information recording / reproducing head 800 formed on the substrate 806 is integrated with the slider 703, and a process similar to that of the conventional magnetic head can be used, so that productivity is improved. Further, since the terminals of the respective elements are formed on the substrate 806 integrated with the slider 703, the access of the terminals to the outside becomes easy and the productivity is improved. Further, the information recording / reproducing head 800 can be moved to a desired position on the information recording medium 704, and electromagnetic field information in a nano-sized region corresponding to a recording surface density exceeding 1 Tb / inch ² can be recorded and reproduced. Therefore, a high-density information recording / reproducing apparatus exceeding 1 Tb / inch ² can be provided.

  The present invention can be modified in design without departing from the scope of the claims, and is not limited to the above embodiment. For example, any one of the electromagnetic field detection elements of Modifications 1 and 2 of the first embodiment may be used instead of the electromagnetic field detection elements of the second to fifth embodiments. Moreover, it is good also as an electromagnetic field detection circuit which combined the 2nd-4th. In the above-described embodiment, the facing surfaces of the pair of electrodes are orthogonal to the surfaces of the three insulating layers, but the facing surfaces of the pair of electrodes may be parallel to the surfaces of the three insulating layers.

1 is a perspective configuration diagram of an electromagnetic field detection element according to a first embodiment of the present invention. It is a block diagram at the time of seeing the electromagnetic field detection element 10 of FIG. 1 from the Y-axis direction. It is a figure used in order to demonstrate the principle of AB effect. It is a figure which shows the electromagnetic field detection element of the modification 1 of 1st Embodiment, Comprising: (a) is a perspective block diagram, (b) is a top view. It is a block diagram at the time of seeing the electromagnetic field detection element of the modification 2 of 1st Embodiment from the Y-axis direction. It is the schematic of the electromagnetic field detection circuit which concerns on 2nd Embodiment of this invention. It is a perspective block diagram which shows concretely the relationship between the electromagnetic field detection element of the electromagnetic field detection circuit of FIG. 6, and a magnetic field generation source. It is the schematic of the electromagnetic field detection circuit which concerns on 3rd Embodiment of this invention. It is a perspective block diagram which shows concretely the relationship between the electromagnetic field detection element and electric field generation source of the electromagnetic field detection circuit of FIG. It is the schematic of the electromagnetic field detection circuit which concerns on 4th Embodiment of this invention. It is a perspective block diagram which shows concretely the relationship between the electromagnetic field detection element of the electromagnetic field detection circuit of FIG. 10, and a semiconductor laser element. It is the schematic of the electromagnetic field detection circuit which concerns on the modification of 4th Embodiment of this invention. It is a front block diagram which shows the magnetic recording / reproducing head based on 5th Embodiment of this invention. It is a figure for demonstrating the generation principle of the electromagnetic field by the electromagnetic field generating element in the magnetic recording / reproducing head shown in FIG. It is a front block diagram which shows the magnetic recording / reproducing head which concerns on the modification of 5th Embodiment of this invention. It is a perspective view which shows the structure of the principal part of the information recording / reproducing apparatus which concerns on 6th Embodiment of this invention. FIG. 17 is an enlarged perspective view near the information recording / reproducing head of the information recording / reproducing apparatus shown in FIG. 16. FIG. 17 is a diagram for describing operations of recording / reproducing electromagnetic field information performed on an information recording medium by an information recording / reproducing head of the information recording / reproducing apparatus shown in FIG. FIG. 19 is a diagram for explaining a state of electromagnetic field detection when a magnetic recording bit recorded on an information recording track of the information recording medium shown in FIG. 18 passes in the vicinity of an electromagnetic field detection element. 6 is a schematic block diagram for explaining the recording / reproducing operation of the information recording / reproducing apparatus 700. FIG. It is the figure which showed the current-voltage characteristic of the electromagnetic field detection element of the structure substantially the same as the electromagnetic field detection element of FIG. It is the figure which showed the electric current-magnetic field characteristic at the time of applying 10V voltage to the electromagnetic field detection element used in FIG. It is the figure which showed the electric current-magnetic field characteristic at the time of applying 0.5V voltage to the electromagnetic field detection element used in FIG.

Explanation of symbols

1, 21, 31, 41, 51, 61, 81, 91, 806 Substrate 2, 3, 4, 22, 23, 24, 32, 33, 34, 42, 43, 44, 52, 53, 54, 62, 63, 64, 82, 83, 84, 92, 93, 94, 502, 602, 804c, 804d, 804e, 805 Insulating layer 5, 6, 25, 26, 35, 36, 45, 46, 55, 56, 65 , 66, 85, 86, 303d, 303e, 504, 505, 604, 605, 802a, 803a, 803b, 804a, 804b Electrode 5a, 6a Opposing surface 7, 8 Boundary surface 10, 20, 30, 40, 50, 60 , 70, 80, 90, 804 Electromagnetic field detection element 11 Electron beam source 12 Electron beam detector 100, 200, 300, 400 Electromagnetic field detection circuit 101, 201, 301, 401 Electromagnetic field detection sensor 102 202, 302, 401 Phase control circuit 103 Magnetic field generation source 103a Thin metal wires 104, 204, 304, 404 Reference resistors 105, 205, 305, 405 Constant voltage power supply circuits 106, 206, 306, 406 Signal amplifiers 107, 207, 307, 407 Lock-in detector 108, 208, 308, 408, 903 Output terminal 109, 110, 209, 210, 309, 310, 409, 410 Modulator signal transmitter 111, 112 V / I converter 113, 213, 313, 413 Switch 114, 214, 314, 414 Hold circuit 115, 215, 315, 415 Switch circuit 116, 216, 316, 416 Resistance 203 Electric field generation source 211, 311, 411 Voltage generation circuit 303, 403, 802 Semiconductor laser element 303a Distribution Type Bragg Projector 303c Laser light oscillator 303f Active region 317, 417 Photodetector 318, 418 Laser drive circuit 319, 419 Laser drive current output circuit 320, 420, 421, 902 Input terminal 500, 600, 800 Information recording / reproducing head 501, 601 and 803 Electromagnetic field generating elements 503 and 603 Insulators 506, 606 and 803c Conductor layer 700 Information recording / reproducing apparatus 701 Actuator 702 Arm 703 Slider 704 Information recording medium 704a Recording surface 704b Information recording track 704c Magnetic recording bit 801 Air bearing structure 901 Recording / reproduction control terminal 904 Recording / reproduction control unit 905 Data recording unit 906 Data reproduction unit 907 Laser emission unit 908 Laser drive unit 909 Electromagnetic field generation unit 910 Current / voltage control unit 911 Electromagnetic field detection

Claims (23)

A pair of opposing electrodes arranged in the insulating region so as to have opposing surfaces facing each other;
It is sandwiched between the pair of opposing electrodes so as to be within the overlapping range while being separated from both end boundaries of the overlapping range of the opposing surface with respect to one direction along the opposing surface, and among the insulating regions, An electromagnetic field detection element comprising: a first insulator having a larger breakdown electric field than a portion sandwiched between a pair of counter electrodes. A pair of opposing electrodes arranged in the insulating region so as to have opposing surfaces facing each other;
A first insulator that is sandwiched between the pair of counter electrodes and has a greater breakdown electric field than a portion of the insulating region that is sandwiched between the pair of counter electrodes;
When an electric field having a magnitude that does not cause dielectric breakdown of the first insulator while applying dielectric breakdown to the portion sandwiched between the pair of counter electrodes in the insulating region, An electromagnetic field detecting element, wherein two ballistic current paths are formed between the pair of counter electrodes to sandwich the first insulator.   In the insulating region, the portion sandwiched between the pair of counter electrodes is provided with second and third insulators that contact the first insulator while sandwiching the first insulator. The electromagnetic field detection element according to claim 1, wherein the electromagnetic field detection element is provided.   4. The width of the second and third insulators in one direction along the opposing surface is equal to or less than the mean free path of electrons in the conductive material constituting the pair of opposing electrodes. The electromagnetic field detection element according to 1.   5. The electromagnetic field detection element according to claim 3, wherein the second and third insulators are in contact with both of the two opposing surfaces of the pair of opposing electrodes.   The electromagnetic field detection element according to claim 3, wherein the first to third insulators form a laminated structure having surfaces parallel to each other.   The electromagnetic field detection element according to claim 3, wherein the facing surface is orthogonal to the surfaces of the first to third insulators.   The electromagnetic field detection element according to claim 3, wherein at least one of the first to third insulators is made of a material having a magnetic permeability of 3 or more.   The electromagnetic field detection element according to claim 3, wherein at least one of the first to third insulators is made of a material having a dielectric constant of 4 or more.   10. The electromagnetic field detection element according to claim 1, wherein the shortest distance between the two opposing surfaces of the pair of opposing electrodes is 100 nm or less.   2. The width of the first insulator in one direction along the opposing surface is less than or equal to twice the mean free path of electrons in the conductive material constituting the pair of opposing electrodes. The electromagnetic field detection element of any one of 10-10.   The width of the first insulator in one direction along the opposing surface is equal to or less than the mean free path of electrons in the conductive material constituting the pair of opposing electrodes. Electromagnetic field detection element.   The electromagnetic field detection element according to claim 1, wherein at least two step portions are formed on the facing surface.   The electromagnetic field according to any one of claims 1 to 13, wherein the first insulator is in contact with at least one of the two opposing surfaces of the pair of opposing electrodes. Detection element. The electromagnetic field detection element according to any one of claims 1 to 14,
An electromagnetic field detection comprising: a phase shift member for shifting the phase of a carrier passing through at least one of two current paths formed between the pair of counter electrodes in the electromagnetic field detection element. Sensor.   The electromagnetic field detection sensor according to claim 15, wherein the phase shift member is a magnetic field generation source.   The electromagnetic field detection sensor according to claim 15, wherein the phase shift member is an electric field generation source.   The electromagnetic field detection sensor according to claim 15, wherein the phase shift member is an electromagnetic wave generation source.   The electromagnetic field detection sensor according to claim 15, wherein the phase shift member is a near-field generation source. The electromagnetic field detection sensor according to any one of claims 15 to 19,
An electromagnetic field detection circuit comprising: a phase control circuit that controls a phase shift amount of the carrier by the phase shift member. An electromagnetic field generating element for recording electromagnetic field information on an information recording medium;
15. A magnetic recording / reproducing head comprising: the electromagnetic field detecting element according to claim 1 that reads electromagnetic field information recorded on an information recording medium.   The information recording / reproducing head according to claim 21, wherein the electromagnetic field detecting element and the electromagnetic field generating element are integrally formed with a slider. An information recording / reproducing head according to claim 21 or 22,
An information recording / reproducing apparatus comprising: moving means for moving the information recording / reproducing head to a predetermined position on the information recording medium.

Images