Multiparticle Entanglement Dynamics of Quantum Chaos in a Bose-Einstein condensate

TL;DR

This paper explores how quantum entanglement evolves in a Bose-Einstein condensate under chaotic dynamics, linking classical chaos measures with quantum Fisher information and analyzing quantum phase transitions.

Contribution

It introduces a beyond mean-field approach to connect classical chaos indicators with quantum entanglement dynamics in Bose-Einstein condensates.

Findings

Quantum Fisher information reflects entanglement dynamics in chaotic regimes.

Classical Lyapunov exponents correlate with the validity of the quantum approximation.

Identifies critical points in quantum phase transitions using beyond mean-field methods.

Abstract

We study the particle-entanglement dynamics witnessed by the quantum Fisher information (QFI) of a trapped Bose-Einstein condensate governed by the kicked rotor Hamiltonian. The dynamics is investigated with a beyond mean-field approach. We link the time scales of the validity of this approximation in, both, classical regular and chaotic regions, with the maximum Lyapunov exponents of the classical system. This establishes an effective connection between the classical chaos and the QFI. We finally study the critical point of a quantum phase transition using the beyond mean-field approximation by considering a two-mode bosonic Josephson junction with attractive interparticle interaction.