Salmon Will, Gustin Chris, Settineri Alessio, Di Stefano Omar, Zueco David, Savasta Salvatore, Nori Franco, Hughes Stephen
Department of Physics, Engineering Physics and Astronomy, Queen's University, Kingston ON K7L 3N6, Canada.
Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
Nanophotonics. 2022 Mar 28;11(8):1573-1590. doi: 10.1515/nanoph-2021-0718. eCollection 2022 Mar.
A quantum dipole interacting with an optical cavity is one of the key models in cavity quantum electrodynamics (cavity-QED). To treat this system theoretically, the typical approach is to truncate the dipole to two levels. However, it has been shown that in the ultrastrong-coupling regime, this truncation naively destroys gauge invariance. By truncating in a manner consistent with the gauge principle, we introduce master equations for open systems to compute gauge-invariant emission spectra, photon flux rates, and quantum correlation functions which show significant disagreement with previous results obtained using the standard quantum Rabi model. Explicit examples are shown using both the dipole gauge and the Coulomb gauge.
一个与光学腔相互作用的量子偶极子是腔量子电动力学（腔QED）中的关键模型之一。从理论上处理这个系统时，典型的方法是将偶极子截断为两个能级。然而，已经证明在超强耦合 regime 中，这种截断会天真地破坏规范不变性。通过以与规范原理一致的方式进行截断，我们引入了开放系统的主方程来计算规范不变的发射光谱、光子通量率和量子关联函数，这些结果与使用标准量子拉比模型获得的先前结果有显著差异。使用偶极规范和库仑规范都给出了具体例子。
