Based on a Liouville-space formulation of open systems, we present a solution to the quantum master equation of two coupled optical waveguides with varying loss. The periodic modulation of the Markovian loss of one of them yields a passive $\mathcal{PT}$-symmetric Floquet system that, at resonance, shows a strong reduction of the required loss for the $\mathcal{PT}$ symmetry to be broken. We showcase this transition for a multiphoton state, and we show how to physically implement the modulated loss with reservoir engineering of a set of bath modes.

中文翻译：

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被动PT对称Floquet耦合器

基于开放系统的刘维尔空间公式，我们提出了具有不同损耗的两个耦合光波导的量子主方程的解。其中之一的马尔可夫损失的周期性调制产生被动$\mathcal{PT}$- 对称的 Floquet 系统，在共振时，显示出所需的损耗大大减少 $\mathcal{PT}$对称性被打破。我们展示了多光子状态的这种转变，并展示了如何通过一组浴模式的储层工程物理实现调制损失。