arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1311.1963quant-ph
收藏

优化三量子比特非破坏宇称测量的随机主方程分析

Stochastic Master Equation Analysis of Optimized Three-Qubit Nondemolition Parity Measurement

L. Tornberg, Sh. Barzanjeh, David P. DiVincenzo

摘要:

我们分析了电路量子电动力学中三个超导量子比特态的直接宇称测量。从反射/透射的微波辐射的零差测量推断奇偶性,并且在测量奇偶性而不需要任何量子线路操作或辅助量子比特的意义上,测量是直接的。量子比特耦合到两个谐振腔模式,允许发射辐射的稳态满足必要条件以充当奇偶校验的指针状态。然而,瞬态动力学违反了这些条件,我们分析了这种不利影响,并表明它可以克服在弱测量信号的限制。我们的分析表明,与适度的后选择,它是可能的,以达到95%的保真度的后测量状态。我们相信,这种类型的测量可以作为一个基准,为未来的纠错协议在一个可扩展的架构。

英文摘要:

We analyze a direct parity measurement of the state of three superconducting qubits in circuit quantum electrodynamics. The parity is inferred from a homodyne measurement of the reflected/transmitted microwave radiation and the measurement is direct in the sense that the parity is measured without the need for any quantum circuit operations or for ancilla qubits. Qubits are coupled to two resonant cavity modes, allowing the steady state of the emitted radiation to satisfy the necessary conditions to act as a pointer state for the parity. However, the transient dynamics violates these conditions and we analyze this detrimental effect and show that it can be overcome in the limit of weak measurement signal. Our analysis shows that, with a moderate degree of post-selection, it is possible to achieve post-measurement states with fidelity of order 95%. We believe that this type of measurement could serve as a benchmark for future error-correction protocols in a scalable architecture.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑