Quantum error mitigation in quantum annealing

TL;DR

This paper introduces quantum error mitigation techniques specifically for quantum annealing, utilizing Zero-Noise Extrapolation methods to reduce thermal and control errors, validated through experiments on a spin chain model.

Contribution

It adapts Zero-Noise Extrapolation for quantum annealing and demonstrates its effectiveness in mitigating thermal and control errors through experimental validation.

Findings

Successful mitigation of thermal noise in quantum annealing.

Energy-time rescaling reduces control errors in coherent regimes.

ZNE results align with exact calculations over extended annealing times.

Abstract

Quantum Error Mitigation (QEM) presents a promising near-term approach to reduce error when estimating expectation values in quantum computing. Here, we introduce QEM techniques tailored for quantum annealing, using Zero-Noise Extrapolation (ZNE). We implement ZNE through zero-temperature extrapolation as well as energy-time rescaling. We conduct experimental investigations into the quantum critical dynamics of a transverse-field Ising spin chain, demonstrating the successful mitigation of thermal noise through both of these techniques. Moreover, we show that energy-time rescaling effectively mitigates control errors in the coherent regime where the effect of thermal noise is minimal. Our ZNE results agree with exact calculations of the coherent evolution over a range of annealing times that exceeds the coherent annealing range by almost an order of magnitude.