Information Gain and Loss for a Quantum Maxwell's Demon
Information Gain and Loss for a Quantum Maxwell's Demon
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DOI：
10.1103/physrevlett.121.030604
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发表时间：
2018-07-17
影响因子：
8.6
通讯作者：
Murch, K. W.
中科院分区：
文献类型：
--
作者：
Naghiloo, M.;Alonso, J. J.;Murch, K. W.
我们利用连续弱测量的超导量子比特的实验研究量子麦克斯韦的恶魔的信息动力学。我们展示了如何使用量子相干反馈将可以跟踪量子比特的单量子轨迹的恶魔获得的信息转换为工作。我们利用沿着单轨道获得的信息验证了一个带反馈的量子涨落定理的有效性。我们证明，特别是，量子反作用可以导致信息的损失，在不完美的测量。此外，我们通过改变量子比特的初始纯度来探测信息增益和损失之间的过渡。
We use continuous weak measurements of a driven superconducting qubit to experimentally study the information dynamics of a quantum Maxwell's demon. We show how information gained by a demon who can track single quantum trajectories of the qubit can be converted into work using quantum coherent feedback. We verify the validity of a quantum fluctuation theorem with feedback by utilizing information obtained along single trajectories. We demonstrate, in particular, that quantum backaction can lead to a loss of information in imperfect measurements. We furthermore probe the transition between information gain and loss by varying the initial purity of the qubit.