Mode-dependent-loss model for multimode photon-subtracted states
Mode-dependent-loss model for multimode photon-subtracted states
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DOI：
10.1103/physreva.100.023828
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发表时间：
2019-05
影响因子：
2.9
通讯作者：
M. Walschaers;Y. Ra;N. Treps
中科院分区：
文献类型：
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作者：
M. Walschaers;Y. Ra;N. Treps
多模光子相减为连续变量量子光学中构造大的非高斯量子态提供了一种实验可行的选择。态的非高斯特征可以导致量子理论中更奇异的方面，例如维格纳函数的负性。然而，具有如此精细量子特性的状态的回报是它们对退相干的敏感性。在本文中，我们提出了一个通用的模型，在一个纯粹的光学设置：损失的退相干处理最重要的来源。我们使用开放的量子系统和主方程的框架来描述损失在$n$-光子减去多模状态，其中每个光子可以在任意模式下减去。作为一个主要的结果，我们发现，模式相关的损失和光子减法一般不交换。特别地，损耗不仅降低了状态的纯度，而且还改变了其非高斯特征的模态结构。然后，我们进行了详细的研究，单光子减法从多模高斯态，这是一个设置，在当今的实验范围内。
Multimode photon subtraction provides an experimentally feasible option to construct large non-Gaussian quantum states in continuous variable quantum optics. The non-Gaussian features of the state can lead towards the more exotic aspects of quantum theory, such as negativity of the Wigner function. However, the payoff for states with such delicate quantum properties is their sensitivity to decoherence. In this paper, we present a general model that treats the most important source of decoherence in a purely optical setting: losses. We use the framework of open quantum systems and master equations to describe losses in $n$-photon-subtracted multimode states, where each photon can be subtracted in an arbitrary mode. As a main result, we find that mode-dependent losses and photon subtraction generally do not commute. In particular, the losses do not only reduce the purity of the state, they also change the modal structure of its non-Gaussian features. We then conduct a detailed study of single-photon subtraction from a multimode Gaussian state, which is a setting that lies within the reach of present-day experiments.