Analyzing the impact of time-correlated noise on zero-noise extrapolation

TL;DR

This paper examines how time-correlated noise affects zero-noise extrapolation in quantum computing, revealing challenges with local scaling methods and proposing global techniques and gate Trotterization as more reliable solutions.

Contribution

It analyzes the impact of time-correlated noise on zero-noise extrapolation and introduces global noise scaling methods and gate Trotterization to improve mitigation.

Findings

Time-correlated noise is harder to mitigate than white noise.

Global noise scaling methods are more reliable under time-correlated noise.

Gate Trotterization offers a new noise scaling technique.

Abstract

Zero-noise extrapolation is a quantum error mitigation technique that has typically been studied under the ideal approximation that the noise acting on a quantum device is not time-correlated. In this work, we investigate the feasibility and performance of zero-noise extrapolation in the presence of time-correlated noise. We show that, in contrast to white noise, time-correlated noise is harder to mitigate via zero-noise extrapolation because it is difficult to scale the noise level without also modifying its spectral distribution. This limitation is particularly strong if "local" gate-level methods are applied for noise scaling. However, we find that "global" noise scaling methods, e.g., global unitary folding, can be sufficiently reliable even in the presence of time-correlated noise. We also introduce gate Trotterization as a new noise scaling technique that may be of independent interest.