Undoing measurement-induced dephasing in circuit QED
Undoing measurement-induced dephasing in circuit QED
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DOI：
10.1103/physreva.85.052318
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发表时间：
2012-05-24
影响因子：
2.9
通讯作者：
Johansson, G.
中科院分区：
文献类型：
--
作者：
Kockum, A. Frisk;Tornberg, L.;Johansson, G.
我们分析了在电路量子电动力学中的超导Qubits上的同伴检测和光电检测的背部。尽管这两种测量方案都以随机相旋转的形式产生了背部，从而导致脱落，但我们表明，只要完全解释了测量信号，就可以完全撤消。该结果在早期的物理上得到改善。 Rev. A 82，012329（2010）]，表明可以提出的方法可以实现完美的两分四分之一的奇偶校验测量。我们在单个量子位上提出了一个基准测量实验，以使用同源性检测来证明该方法。通过分析检测器的有限测量效率和放大器的带宽，我们表明，查看效果所需的参数值在现有技术的范围内。
We analyze the backaction of homodyne detection and photodetection on superconducting qubits in circuit quantum electrodynamics. Although both measurement schemes give rise to backaction in the form of stochastic phase rotations, which leads to dephasing, we show that this can be perfectly undone provided that the measurement signal is fully accounted for. This result improves on an earlier one [Phys. Rev. A 82, 012329 (2010)], showing that the method suggested can be made to realize a perfect two-qubit parity measurement. We propose a benchmarking experiment on a single qubit to demonstrate the method using homodyne detection. By analyzing the limited measurement efficiency of the detector and bandwidth of the amplifier, we show that the parameter values necessary to see the effect are within the limits of existing technology.