Error mitigation of shot-to-shot fluctuations in analog quantum simulators

TL;DR

This paper introduces an error mitigation method for analog quantum simulators that suppresses shot-to-shot fluctuations, extending coherence times and improving simulation accuracy in quantum many-body systems.

Contribution

The authors propose a noise amplification and extrapolation technique to mitigate shot-to-shot parameter fluctuations in analog quantum simulators, validated experimentally and numerically.

Findings

Extended the coherence time of a 27-ion trapped-ion quantum simulator threefold.

Predicted significant enhancement of many-body coherence time in Rydberg atom arrays.

Demonstrated effective error suppression for realistic noise distributions.

Abstract

Analog quantum simulators have provided key insights into quantum many-body dynamics. However, in such systems, both coherent and incoherent errors limit their scalability, hindering simulations in regimes that challenge classical simulations. In this work, we introduce an error mitigation technique that addresses and effectively suppresses a key source of error in leading simulator platforms: shot-to-shot fluctuations in the parameters for the Hamiltonian governing the system dynamics. We rigorously prove that amplifying this shot-to-shot noise and extrapolating to the zero-noise limit recovers noiseless results for realistic noise distributions. Experimentally, we demonstrate this technique on a 27-ion trapped-ion quantum simulator, extending the two-qubit exchange oscillation lifetime threefold. Numerically, we predict a significant enhancement in the effective many-body coherence time for Rydberg atom arrays under realistic conditions. Our scheme provides a possible route towards extending the effective coherence time in analog quantum experiments, enabling deeper explorations of quantum many-body dynamics.