Calculating ground state using QITE and mitigating depolarizing noise

[KingHosung]

Team Name:

Hosungland

Hosung Lee, Kihyeon Kim, Dohyun Song

Project Description:

Calculating ground state using QITE and mitigating depolarizing noise

abstract

We calculate the ground state of quantum models by applying the latest quantum algorithms called QITE and random compiling. QITE can calculate the ground state without using ansatz and is a much better algorithm than VQE which was commonly used. We also used random compiling to correct fundamental errors in quantum computers. 448 random instances were used and it was confirmed that the mitigated data was much closer to the exact value than the original data.

1.What is QITE?

QITE = Quantum Imaginary Time Evolution
Idea: linearization to compute generators of unitary of step 𝑛+1, from measured expectation values at step 𝑛.

2.QITE vs ITE in Transverse Ising Model

3.Why QITE ?

When using VQE algorithm, creating ansatz is a complicated problem, and the classical part of the algorithm also requires optimization.

QITE algorithm needs no ansatz.

4.Error mitigation - random compiling

5.Error mitigation - zero noise extrapolation

6.Real time evolution result using Error Mitigation

7.Ground State Energy of 𝐻_2 using QITE&VQE

8.Possible Problems with QITE

As the beta increases, the circuit repeats more, so noise of hardware is increased.
Also, the accuracy of Trotterization decreases.

9.Importance of Selecting Parameter

Due to the hardware noise, proper Δ𝜏 must be set.

10.Pulse Calibration

Additionally, to solve the basic problem of noise in hardware, we should apply an algorithm such as pulse-level QITE.

Presentation:

Please watch this video !!!

PPT

video

Source code:

https://github.com/KingHosung/qHack_2022

Reference

Determining eigenstates and thermal states on a quantum computer using quantum imaginary time evolution

Simulating quantum many-body dynamics on a current digital quantum computer

Mitigating Depolarizing Noise on Quantum Computers with Noise-Estimation Circuits

Which challenges/prizes would you like to submit your project for?

IBM Qiskit Challenge, Quantum Chemistry Challenge, Science Challenge, Simulation Challenge, Young Scientist Challenge

[isaacdevlugt]

Hey @KingHosung! The submission deadline is February 25 at 17h00. Feel free to update your submission (e.g., including a source code link) up until that point 😄

Good luck!

[shfd27]

Hey @KingHosung! The submission deadline is February 25 at 17h00. Feel free to update your submission (e.g., including a source code link) up until that point 😄

Good luck!

Thank you for your reply.