Robustness-optimized quantum error correction

TL;DR

This paper introduces an optimization-based method to enhance quantum error correction robustness against faults, tailored for smaller quantum devices where error sources are well-understood, potentially improving near-term quantum experiments.

Contribution

The paper presents a novel optimization approach that maximizes fault robustness in quantum error correction, specifically designed for small-scale quantum devices.

Findings

The approach improves fault tolerance in a three-qubit model.

Near-term experiments can benefit from more robust error correction protocols.

The method is inspired by recent experimental insights into fault sources.

Abstract

Quantum error correction codes are usually designed to correct errors regardless of their physical origins. In large-scale devices, this is an essential feature. In smaller-scale devices, however, the main error sources are often understood, and this knowledge could be exploited for more efficient error correction. Optimizing the quantum error correction protocol is therefore a promising strategy in smaller devices. Typically, this involves tailoring the protocol to a given decoherence channel by solving an appropriate optimization problem. Here we introduce a new optimization-based approach, which maximizes the robustness to faults in the recovery. Our approach is inspired by recent experiments, where such faults have been a significant source of logical errors. We illustrate this approach with a three-qubit model, and show how near-term experiments could benefit from more robust quantum error correction protocols.