Robust shadow estimation
Abstract
Efficiently estimating properties of large and strongly coupled quantum systems is a central focus in many-body physics and quantum information theory. While quantum computers promise speedups for many such tasks, near-term devices are prone to noise that will generally reduce the accuracy of such estimates. Here we show how to mitigate errors in the shadow estimation protocol recently proposed by Huang, Kueng, and Preskill. By adding an experimentally friendly calibration stage to the standard shadow estimation scheme, our robust shadow estimation algorithm can obtain an unbiased estimate of the classical shadow of a quantum system and hence extract many useful properties in a sample-efficient and noise-resilient manner given only minimal assumptions on the experimental conditions. We give rigorous bounds on the sample complexity of our protocol and demonstrate its performance with several numerical experiments.
Cite
@article{arxiv.2011.09636,
title = {Robust shadow estimation},
author = {Senrui Chen and Wenjun Yu and Pei Zeng and Steven T. Flammia},
journal= {arXiv preprint arXiv:2011.09636},
year = {2021}
}
Comments
39 pages, 10 figures. We add numerical experiments with practical gate-dependent noise models to justify the wide application of our robust protocol