[Information Challenge] Improving VQE accuracy for H4 molecule with shot limits

[Dran-Z]

Team name:
CloudKite

Team members:
Yunzhe Zheng

Applied challenge:
Information Challenge

Project Description:
In this project, we improved the VQE accuracy for the H4 molecule with given shot limits. We investigated the performance of VQE from ansatz implementation, measurement optimization, and optimizer choice. Combining all these improvements, our algorithm reached quasi-chemical accuracy(~3mH) with a 1e8 shot limit, and chemical accuracy is guaranteed given a more relaxed shot limit(~5e8).

Besides, we propose error mitigation approaches for VQE on the real noisy quantum devices. Apart from the common approaches like readout-error correction and zero-noise extrapolation, we propose to mitigate depolarizing error using error-estimation circuits.

Presentation:
here
Source code:
here