Parity–time (PT) symmetry, an interesting concept originally introduced in quantum mechanics, has been extended to many other branches of physics. Besides its demonstrations in optics and electronics, the study of PT-symmetric mechanics is growing rapidly. To date, most PT-symmetric mechanical systems have relatively large size and low operating frequency, which limits their applications in high-speed sensing and signal processing. Here, we propose a PT-symmetric mechanical system with gain/loss provided by the cavity optomechanical effect, which can overcome those limitations. We theoretically analyze and numerically simulate the optical control of PT-symmetric optomechanical systems that consist of two or more mechanical resonators. We find the property of unidirectional reflection in these systems, which may pave the way for the study of topological acoustics and phononic signal processing.

中文翻译：

---

腔光力学效应引起的奇偶时间对称机械系统

奇偶时间（PT）对称性是最初在量子力学中引入的一个有趣概念，现已扩展到物理的许多其他分支。除了在光学和电子领域的演示外，对PT对称力学的研究也在迅速发展。迄今为止，大多数PT对称机械系统具有相对较大的尺寸和较低的工作频率，这限制了它们在高速传感和信号处理中的应用。在这里，我们提出了一种具有腔光学机械效应所带来的增益/损耗的PT对称机械系统，可以克服这些局限性。我们从理论上分析和数值模拟了由两个或多个机械谐振器组成的PT对称光机械系统的光学控制。我们在这些系统中发现了单向反射的特性，