# Effect of system energy on quantum signatures of chaos in the two-photon Dicke model

## TL;DR

This study investigates how increasing system energy enhances the ability to distinguish chaos from regularity in the quantum two-photon Dicke model using entanglement entropy and Husimi Q distribution.

## Contribution

It demonstrates that higher system energy improves the quantum signatures of chaos, aligning quantum measures more closely with classical chaos indicators.

## Key findings

- Entanglement entropy becomes more distinguishable at higher energies.
- Husimi Q distribution disperses faster in chaotic regions at higher energies.
- Quantum chaos signatures are enhanced with increased system energy.

## Abstract

We have studied entanglement entropy and Husimi $Q$ distribution as a tool to explore chaos in the quantum two-photon Dicke model. With the increase of the energy of system, the linear entanglement entropy of coherent state prepared in the classical chaotic and regular regions become more distinguishable, and the correspondence relationship between the distribution of time-averaged entanglement entropy and the classical Poincar\'{e} section has been improved obviously. Moreover, Husimi $Q$ distribution for the initial states corresponded to the points in the chaotic region in the higher energy system disperses more quickly than that in the lower energy system. Our result imply that higher system energy has contributed to distinguish the chaotic and regular behavior in the quantum two-photon Dicke model.