Improved autonomous error correction using variable dissipation in small logical qubit architectures
Improved autonomous error correction using variable dissipation in small logical qubit architectures
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DOI：
10.1088/2058-9565/abc3cb
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发表时间：
2020-06
影响因子：
6.7
通讯作者：
David Rodríguez Pérez;E. Kapit
中科院分区：
文献类型：
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作者：
David Rodríguez Pérez;E. Kapit
随着时间的推移，超导量子比特的相干时间大大提高。此外，使用工程耗散的小型逻辑量子位体系结构在进一步改善由少量物理量子位组成的逻辑量子位流形的相干性方面显示出很大的希望。然而，小逻辑量子位的最佳工作参数通常还没有得到很好的理解。这项工作通过观察三种不同的复杂性增加的情况，提出了几种寻找优先参数配置的方法。我们首先通过耦合损耗来观察单个量子比特的状态稳定。我们研究了这种纠错方法中的限制因素，以及我们如何通过数值优化与具有有效时变耗散率的有损对象的参数耦合强度来解决这些问题-我们称之为脉冲复位周期。然后，我们将这种更有效的状态稳定方法转换为抽象的三量子位翻转代码，最后查看非常小的逻辑量子位（VSLQ）。通过使用这些技术，我们可以进一步增加不同体系结构的逻辑状态生命周期。我们展示了使用脉冲复位周期优于数值优化的固定参数空间的显著优势。
Coherence times for superconducting qubits have greatly improved over time. Moreover, small logical qubit architectures using engineered dissipation have shown great promise for further improvements in the coherence of a logical qubit manifold comprised of few physical qubits. Nevertheless, optimal working parameters for small logical qubits are generally not well understood. This work presents several approaches to finding preferential parameter configurations by looking at three different cases of increasing complexity. We begin by looking at state stabilization of a single qubit using dissipation via coupling to a lossy object. We look at the limiting factors in this approach to error correction, and how we address those by numerically optimizing the parametric coupling strength with the lossy object having an effective time-varying dissipation rate—we call this a pulse-reset cycle. We then translate this approach to more efficient state stabilization to an abstracted three-qubit flip code, and end by looking at the very small logical qubit (VSLQ). By using these techniques, we can further increase logical state lifetimes for different architectures. We show significant advantages in using a pulse-reset cycle over numerically optimized, fixed parameter spaces.