Department of Physics and Astronomy, Stony Brook University, SUNY, Stony Brook, New York 11794-3800, USA.
Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Phys Rev Lett. 2016 Jan 8;116(1):010501. doi: 10.1103/PhysRevLett.116.010501.
We suggest and demonstrate a protocol which suppresses the low-frequency dephasing by qubit motion, i.e., transfer of the logical qubit of information in a system of n≥2 physical qubits. The protocol requires only the nearest-neighbor coupling and is applicable to different qubit structures. Our analysis of its effectiveness against noises with arbitrary correlations, together with experiments using up to three superconducting qubits, shows that for the realistic uncorrelated noises, qubit motion increases the dephasing time of the logical qubit as √n. In general, the protocol provides a diagnostic tool for measurements of the noise correlations.
我们提出并演示了一种抑制由量子比特运动引起的低频退相的协议，即在 n≥2 个物理量子比特系统中传输逻辑量子比特的信息。该协议仅需要最近邻耦合，并且适用于不同的量子比特结构。我们对其在任意相关噪声下的有效性进行了分析，并结合使用多达三个超导量子比特的实验，表明对于现实的不相关噪声，量子比特运动将逻辑量子比特的退相时间增加为√n。一般来说，该协议为噪声相关性的测量提供了一种诊断工具。
