Long-time fidelity and chaos for a kicked nonlinear oscillator system

TL;DR

This paper investigates the long-term behavior of a nonlinear oscillator system under pulsed excitation, introducing fidelity-based parameters as indicators of quantum chaos and analyzing their chaotic dynamics over time.

Contribution

It introduces new fidelity-based entropic and photon-number parameters to detect quantum chaos in a nonlinear oscillator system, emphasizing long-time behavior.

Findings

Quantum fidelities exhibit classical-like chaos in deep chaos regimes.

Fidelity-like parameters effectively indicate quantum chaos.

Long-time analysis reveals persistent chaotic behavior in the system.

Abstract

We deal with a system comprising a nonlinear (Kerr-like) oscillator excited by a series of ultra-short external pulses. We introduce the fidelity-based entropic parameter that can be used as an indicator of quantum chaos. Moreover, we propose to use the fidelity-like parameter comprising the information about the mean number of photons in the system. We shall concentrate on the long-time behaviour of the parameters discussed, showing that for deep chaos cases the quantum fidelities behave chaotically in the classical sense despite their strictly quantum character.