Compressed quantum error mitigation

TL;DR

This paper presents a quantum error mitigation method using probabilistic error cancellation, applying an optimal denoiser after noisy quantum circuits to improve accuracy in quantum simulations.

Contribution

It introduces a novel error mitigation technique based on an ensemble of circuits with quasiprobability distribution, applicable with arbitrary extra gates.

Findings

Efficient local denoisers can be constructed for simple noise models.

The method effectively improves quantum simulation accuracy for spin chains.

Demonstrated success in digital quantum simulation of time evolution.

Abstract

We introduce a quantum error mitigation technique based on probabilistic error cancellation to eliminate errors which have accumulated during the application of a quantum circuit. Our approach is based on applying an optimal "denoiser" after the action of a noisy circuit and can be performed with an arbitrary number of extra gates. The denoiser is given by an ensemble of circuits distributed with a quasiprobability distribution. For a simple noise model, we show that efficient, local denoisers can be found, and we demonstrate their effectiveness for the digital quantum simulation of the time evolution of simple spin chains.