Implementation-independent sufficient condition of the Knill-Laflamme type for the autonomous protection of logical qudits by strong engineered dissipation
Implementation-independent sufficient condition of the Knill-Laflamme type for the autonomous protection of logical qudits by strong engineered dissipation
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DOI：
10.1103/physreva.98.012317
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发表时间：
2017-11
影响因子：
2.9
通讯作者：
Jae-Mo Lihm;Kyungjoo Noh;U. R. Fischer
中科院分区：
文献类型：
--
作者：
Jae-Mo Lihm;Kyungjoo Noh;U. R. Fischer
自主量子纠错利用量子系统与耗散Ancilla的工程耦合来保护量子逻辑态不受退相干的影响。我们证明了Knill-Laflamme条件，即环境误差算子应该平凡地作用于一个子空间，然后子空间成为码子空间，足以保护逻辑量子数不受马尔可夫噪声的影响。通过显式推导误差随时间和工程耗散强度的变化规律，证明了在大的工程耗散极限下，代码子空间的总Lindbladian演化所引起的误差可以被抑制到很长时间。为了展示我们方法的应用潜力，我们用二项式编码实现了我们的一般理论，这是一类玻色纠错码，并概述了它们如何以完全自主的方式实现以防止微波腔中的光子损失。
Autonomous quantum error correction utilizes the engineered coupling of a quantum system to a dissipative ancilla to protect quantum logical states from decoherence. We show that the Knill-Laflamme condition, stating that the environmental error operators should act trivially on a subspace, which then becomes the code subspace, is sufficient for logical qudits to be protected against Markovian noise. It is proven that the error caused by the total Lindbladian evolution in the code subspace can be suppressed up to very long times in the limit of large engineered dissipation, by explicitly deriving how the error scales with both time and engineered dissipation strength. To demonstrate the potential of our approach for applications, we implement our general theory with binomial codes, a class of bosonic error-correcting codes, and outline how they can be implemented in a fully autonomous manner to protect against photon loss in a microwave cavity.