Robust adaptive measurement scheme for qubit-state preparation
Robust adaptive measurement scheme for qubit-state preparation
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DOI：
10.1103/physreva.86.062331
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发表时间：
2012-08
影响因子：
2.9
通讯作者：
Saki Tanaka;N. Yamamoto
中科院分区：
文献类型：
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作者：
Saki Tanaka;N. Yamamoto
本文重新考虑了Jacobs提出的量子比特态制备的自适应测量方法，并给出了一种即使在状态的幺正演化未知的情况下也能工作的替代方案。其关键思想是自适应地改变测量，使得被测可观测量的本征态之一总是设置在当前状态和目标状态之间，同时本征态收敛到目标。该方案的最大特点是测量强度可以取为常数，这与Jacobs的方法不同，最终使受控状态对幺正演化的不确定性具有良好的鲁棒性。
This paper reconsiders the method of adaptive measurement for qubit state preparation developed by Jacobs and shows an alternative scheme that works even under unknown unitary evolution of the state. The key idea is that the measurement is adaptively changed so that one of the eigenstates of the measured observable is always set between the current and the target states at while that eigenstate converges to the target. The most significant feature of this scheme is that the measurement strength can be taken constant unlike Jacobs' one, which eventually provides fine robustness property of the controlled state against the uncertainty of the unitary evolution.