Nonperturbative Dynamical Casimir Effect in Optomechanical Systems: Vacuum Casimir-Rabi Splittings
Nonperturbative Dynamical Casimir Effect in Optomechanical Systems: Vacuum Casimir-Rabi Splittings
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DOI：
10.1103/physrevx.8.011031
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发表时间：
2018-02-26
影响因子：
12.5
通讯作者：
Savasta, Salvatore
中科院分区：
文献类型：
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作者：
Macri, Vincenzo;Ridolfo, Alessandro;Savasta, Salvatore
我们使用对腔场和振动镜的完全量子力学描述来研究动态卡西米尔效应。我们既不将动力学线性化，也不采用任何参数或微扰近似。通过对完整的光机哈密顿量进行数值对角化，我们表明真空中光子的共振产生是由镜 - 场真空拉比分裂的阶梯所决定的。我们发现真空发射可以源于初始纯机械激发态的自由演化，这类似于激发原子的自发发射。通过考虑对镜子的相干驱动，并使用主方程方法考虑损耗，我们能够研究从弱到超强的光机耦合强度下的动态卡西米尔效应。我们发现，即使机械频率低于腔模频率，也能观察到真空中光子的共振产生。由于在实验中难以实现的高机械频率曾被认为对实现动态卡西米尔效应至关重要，这一结果消除了观察这一长期寻求的效应的主要障碍之一。我们还发现动态卡西米尔效应能够在振动镜和其在真空场中运动所产生的辐射之间产生纠缠，并且会出现真空卡西米尔 - 拉比振荡。最后，我们还表明所有这些发现不仅适用于光机系统，也适用于在完全量子态下运行的参量放大器。
We study the dynamical Casimir effect using a fully quantum-mechanical description of both the cavity field and the oscillating mirror. We do not linearize the dynamics, nor do we adopt any parametric or perturbative approximation. By numerically diagonalizing the full optomechanical Hamiltonian, we show that the resonant generation of photons from the vacuum is determined by a ladder of mirror-field vacuum Rabi splittings. We find that vacuum emission can originate from the free evolution of an initial pure mechanical excited state, in analogy with the spontaneous emission from excited atoms. By considering a coherent drive of the mirror, using a master-equation approach to take losses into account, we are able to study the dynamical Casimir effect for optomechanical coupling strengths ranging from weak to ultrastrong. We find that a resonant production of photons out of the vacuum can be observed even for mechanical frequencies lower than the cavity-mode frequency. Since high mechanical frequencies, which are hard to achieve experimentally, were thought to be imperative for realizing the dynamical Casimir effect, this result removes one of the major obstacles for the observation of this long-sought effect. We also find that the dynamical Casimir effect can create entanglement between the oscillating mirror and the radiation produced by its motion in the vacuum field, and that vacuum Casimir-Rabi oscillations can occur. Finally, we also show that all these findings apply not only to optomechanical systems, but also to parametric amplifiers operating in the fully quantum regime.