Simple Mitigation of Global Depolarizing Errors in Quantum Simulations

TL;DR

This paper introduces a simple error mitigation method for quantum simulations that assumes global depolarizing noise, enabling more accurate results on current quantum devices, demonstrated through physics experiments and simulations.

Contribution

The authors propose a device-independent error mitigation technique based on global depolarizing error models, improving quantum simulation accuracy.

Findings

Successfully extracted meson masses from IBM quantum computers

Effective in mitigating global depolarizing errors in quantum circuits

Applicable to a range of quantum tasks with realistic error models

Abstract

To get the best possible results from current quantum devices error mitigation is essential. In this work we present a simple but effective error mitigation technique based on the assumption that noise in a deep quantum circuit is well described by global depolarizing error channels. By measuring the errors directly on the device, we use an error model ansatz to infer error-free results from noisy data. We highlight the effectiveness of our mitigation via two examples of recent interest in quantum many-body physics: entanglement measurements and real time dynamics of confinement in quantum spin chains. Our technique enables us to get quantitative results from the IBM quantum computers showing signatures of confinement, i.e. we are able to extract the meson masses of the confined excitations which were previously out of reach. Additionally, we show the applicability of this mitigation protocol in a wider setting with numerical simulations of more general tasks using a realistic error model. Our protocol is device-independent, simply implementable and leads to large improvements in results if the global errors are well described by depolarization.