论文标题
没有知识测量的时间延迟的量子反馈和不完全的反馈抑制
Time-delayed quantum feedback and incomplete decoherence suppression with no-knowledge measurement
论文作者
论文摘要
NO-NOW-NOWELGED量子反馈是由Szigeti等人提出的。莱特牧师。 113，020407（2014），作为开放量子系统的基于测量的反馈协议。通过连续测量环境噪声并在系统上进行反馈控制，该协议可以完全逆转测量背面，从而抑制系统的破坏。但是，仅针对瞬时反馈显示了完整的分解取消，这在实际实验中是不切实际的。因此，在这项工作中，我们通过分析非马科维亚平均动力学来概括原始工作，并研究如何通过不可避免的延迟时间降解破裂性抑制。我们介绍了平均动力学的分析表达式，并通过数值分析了连贯驱动的两级系统的延迟反馈的效果，并通过Hermitian耦合操作员耦合到骨浴。我们还发现，当量子标准的统一动力学不通过测量和反馈控件进行通勤时，可以根据延迟时间抑制或放大的分解速率。
The no-knowledge quantum feedback was proposed by Szigeti et al., Phys. Rev. Lett. 113, 020407 (2014), as a measurement-based feedback protocol for decoherence suppression for an open quantum system. By continuously measuring environmental noises and feeding back controls on the system, the protocol can completely reverse the measurement backaction and therefore suppress the system's decoherence. However, the complete decoherence cancellation was shown only for the instantaneous feedback, which is impractical in real experiments. Therefore, in this work, we generalize the original work and investigate how the decoherence suppression can be degraded with unavoidable delay times, by analyzing non-Markovian average dynamics. We present analytical expressions for the average dynamics and numerically analyze the effects of the delayed feedback for a coherently driven two-level system, coupled to a bosonic bath via a Hermitian coupling operator. We also find that, when the qubit's unitary dynamics does not commute with the measurement and feedback controls, the decoherence rate can be either suppressed or amplified, depending on the delay time.
