Departamento de Ciencias, Sección Física, Pontificia Universidad Católica del Perú, Apartado, 1761, Lima, Peru.
Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain.
Sci Rep. 2017 Aug 18;7(1):8774. doi: 10.1038/s41598-017-09110-7.
We study two dispersive regimes of the Dicke model in the dynamics of N two-level atoms interacting with a bosonic mode for long interaction times. Firstly, we analyze the model for the regime in which the qubit frequencies are equal and smaller than the mode frequency, and for values of the coupling strength similar or larger than the mode frequency, namely, the deep strong coupling regime. Secondly, we address an interaction that is dependent on the photon number, where the coupling strength is comparable to the geometric mean of the qubit and mode frequencies. We show that the associated dynamics is analytically tractable and provide useful frameworks with which to analyze the system behavior. In the deep strong coupling regime, we unveil the structure of unexpected resonances for specific values of the coupling, present for N ≥ 2, and in the photon-number-dependent regime we demonstrate that all the nontrivial dynamical behavior occurs in the atomic degrees of freedom for a given Fock state. We verify these assertions with numerical simulations of the qubit population and photon-statistic dynamics.
我们研究了 Dicke 模型在 N 个两能级原子与玻色模相互作用的动力学中的两种耗散机制，对于长时间的相互作用。首先，我们分析了模型在量子比特频率相等且小于模式频率的情况下，以及在耦合强度与模式频率相似或更大的情况下，即深强耦合 regime 的情况。其次，我们研究了依赖于光子数的相互作用，其中耦合强度与量子比特和模式频率的几何平均值相当。我们表明，相关的动力学是可解析处理的，并提供了有用的框架来分析系统行为。在深强耦合 regime 中，我们揭示了特定耦合值下的意外共振结构，对于 N≥2 是存在的，而在光子数依赖的 regime 中，我们证明了在给定的 Fock 态下，所有非平凡的动力学行为都发生在原子自由度中。我们通过对量子比特种群和光子统计动力学的数值模拟验证了这些断言。
