Nonergodicity in the Anisotropic Dicke Model

作者：Buijsman Wouter; Gritsev Vladimir; Sprik Rudolf

来源：Physical Review Letters, 2017, 118(8): 080601.

DOI：10.1103/PhysRevLett.118.080601

We study the ergodic-nonergodic transition in a generalized Dicke model with independent corotating and counterrotating light-matter coupling terms. By studying level statistics, the average ratio of consecutive level spacings, and the quantum butterfly effect (out-of-time correlation) as a dynamical probe, we show that the ergodic-nonergodic transition in the Dicke model is a consequence of the proximity to the integrable limit of the model when one of the couplings is set to zero. This can be interpreted as a hint for the existence of a quantum analogue of the classical Kolmogorov-Arnold-Moser theorem. In addition, we show that there is no intrinsic relation between the ergodic-nonergodic transition and the precursors of the normal-superradiant quantum phase transition.

• 出版日期2017-2-23