The Lindblad form of the master equation has proven to be one of the most convenient ways to describe the impact of an environment interacting with a quantum system of interest. For single systems the jump operators characterizing these interactions usually take simple forms with a clear interpretation. However, for coupled systems these operators take significantly different forms and the full dynamics cannot be described by jump operators acting on the individual subsystems only. In this work, we investigate the differences between a common phenomenological model for the master equation and the more rigorous dressed-state master equation for optomechanical systems. We provide an analytical method to obtain the absorption spectrum of the system for both models and show the breakdown of the phenomenological model in both the bad cavity and the ultra-strong coupling limit. We present a careful discussion of the indirect dephasing of the optical cavity in both models and its role in the differences of their predicted absorption spectra. Our work provides a simple experimental test to determine whether the simpler phenomenological model can be used to describe the system and is a step forward toward a better understanding of the role of the coupling between subsystems for open-quantum-system dynamics.

已经证明，主方程的Lindblad形式是描述环境与感兴趣的量子系统相互作用的影响的最便捷方法之一。对于单个系统，表征这些交互的跳转运算符通常采用简单的形式并具有清晰的解释。但是，对于耦合系统，这些运算符采取截然不同的形式，并且仅通过作用于各个子系统的跳转运算符就无法描述全部动态。在这项工作中，我们研究了用于主方程的常见现象模型与用于光机械系统的更为严格的穿戴状态主方程之间的差异。我们提供了一种分析方法来获得两个模型的系统吸收光谱，并显示了在坏腔和超强耦合极限下现象学模型的分解。我们目前对两种模型中光学腔的间接移相及其在其预测吸收光谱差异中的作用进行了仔细的讨论。我们的工作提供了一个简单的实验测试，以确定是否可以使用更简单的现象学模型来描述系统，这是朝着更好地理解开放式量子系统动力学子系统之间的耦合作用迈出的一步。