On-demand maximally entangled states with a parity meter and continuous feedback
On-demand maximally entangled states with a parity meter and continuous feedback
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DOI：
10.1103/physrevb.90.155438
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发表时间：
2014-07
影响因子：
3.7
通讯作者：
Clemens Meyer zu Rheda;G. Haack;A. Romito
中科院分区：
文献类型：
--
作者：
Clemens Meyer zu Rheda;G. Haack;A. Romito
按需产生最大纠缠态是量子信息处理的基石之一。宇称测量可以用来产生贝尔态，并且已经通过电子马赫-曾德尔干涉仪等来实现。然而，在两个宇称子空间中的一个中，测量引起的退相过程必然会损害纠缠的产生。在这项工作中，我们提出了两种不同的计划连续反馈的奇偶校验测量。它们使我们能够避免测量引起的失相过程和实验上不可避免的失相，例如由于控制量子位初始化的栅极电压的波动。我们证明了在两个宇称子空间中都可以产生最大纠缠定态。重要的是，我们提出的测量方案是有效的奇偶校验测量的反馈回路在各种固态环境中的实施。
Generating on-demand maximally entangled states is one of the corner stones for quantum information processing. Parity measurements can serve to create Bell states and have been implemented via an electronic Mach-Zehnder interferometer among others. However, the entanglement generation is necessarily harmed by measurement induced dephasing processes in one of the two parity subspace. In this work, we propose two different schemes of continuous feedback for a parity measurement. They enable us to avoid both the measurement-induced dephasing process and the experimentally unavoidable dephasing, e.g. due to fluctuations of the gate voltages controlling the initialization of the qubits. We show that we can generate maximally entangled steady states in both parity subspaces. Importantly, the measurement scheme we propose is valid for implementation of parity measurements with feedback loops in various solid-state environments.