近日，瑞士BM量子公司的Bence Hetényi及其研究团队取得一项新进展。经过不懈努力，他们成功实现自旋量子比特的定制化量子纠错。相关研究成果已于2024年3月26日在国际知名学术期刊《物理评论A》上发表。

在这项研究中，研究人员着眼于一类先进的纠错码，这类码仅需最近邻连通性，且能够通过最小权重完美匹配实现快速解码。与表面码相较，XZZX码、低连通性表面码、XYZ2匹配码和Floquet码在错误阈值、连通性或是逻辑量子比特编码方面均展现出不同的优势。研究人员针对这些纠错码，提出了相应的自旋量子比特布局方案，并特别考虑了自旋读出时所需的参考量子比特。此外，他们还深入探讨了这些码在电路级噪声下的性能表现，包括空转阶段门、读出过程以及量子比特退相干过程中可能出现的不同错误率。

据悉，半导体结构中的自旋量子比特为大规模二维集成带来了曙光，有望实现在同一芯片上集成控制电子器件的壮举。然而，在此平台上进行量子纠错操作时，必须充分考虑自旋量子比特的独特特性。例如，量子比特的读出过程涉及一个额外的量子比特，如对退相干的强偏置。

附：英文原文

Title: Tailoring quantum error correction to spin qubits

Author: Bence Hetényi, James R. Wootton

Issue&Volume: 2024/03/26

Abstract: Spin qubits in semiconductor structures bring the promise of large-scale two-dimensional integration, with the possibility to incorporate the control electronics on the same chip. In order to perform error correction on this platform, the characteristic features of spin qubits need to be accounted for. For example, qubit readout involves an additional qubit which necessitates careful reconsideration of the qubit layout. The noise affecting spin qubits has further peculiarities such as the strong bias towards dephasing. In this work we consider state-of-the-art error correction codes that require only nearest-neighbor connectivity and are amenable to fast decoding via minimum-weight perfect matching. Compared to the surface code, the XZZX code, the reduced-connectivity surface code, the XYZ² matching code, and the Floquet code all bring different advantages in terms of error threshold, connectivity, or logical qubit encoding. We present the spin-qubit layout required for each of these error correction codes, accounting for reference qubits required for spin readout. The performance of these codes is studied under circuit-level noise accounting for distinct error rates for gates, readout, and qubit decoherence during idling stages.

DOI: 10.1103/PhysRevA.109.032433

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.032433