Quantum state tomography via mutually unbiased measurements in driven cavity QED systems
Quantum state tomography via mutually unbiased measurements in driven cavity QED systems
复制标题
通过驱动腔 QED 系统中的相互无偏测量进行量子态断层扫描
DOI：
10.1088/1367-2630/18/4/043013
复制
发表时间：
2016-04-12
影响因子：
3.3
通讯作者：
Guo, Guang-Can
中科院分区：
文献类型：
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作者：
Yuan, Hao;Zhou, Zheng-Wei;Guo, Guang-Can
本文提出了一种在色散耦合驱动腔QED系统中通过相互无偏测量实现量子比特和量子比特态的量子层析成像的可行方案。我们首先表明，在相互无偏基地（MUBs）的测量实际上是通过执行适当的酉变换后，将检测到的状态投影到计算基础上来实现的。然后，可以通过检测驱动腔的稳态透射谱（SSTS）来确定测量结果。发现每个MUB的所有测量结果（即，每个检测状态的密度矩阵的所有对角元素）可以仅从一种SSTS中直接读出。以这种方式，我们数值证明，示例量子比特和qutrit状态可以分别重建为0.952和0.961，分别。我们的提议可以直接扩展到其他高维量子系统，只要它们的MUB存在。
We present a feasible proposal for quantum tomography of qubit and qutrit states via mutually unbiased measurements in dispersively coupled driven cavity QED systems. We first show that measurements in the mutually unbiased bases (MUBs) are practically implemented by projecting the detected states onto the computational basis after performing appropriate unitary transformations. The measurement outcomes can then be determined by detecting the steady-state transmission spectra (SSTS) of the driven cavity. It is found that all the measurement outcomes for each MUB (i.e., all the diagonal elements of the density matrix of each detected state) can be read out directly from only one kind of SSTS. In this way, we numerically demonstrate that the exemplified qubit and qutrit states can be reconstructed with the fidelities 0.952 and 0.961, respectively. Our proposal could be straightforwardly extended to other high-dimensional quantum systems provided that their MUBs exist.