Quantum squeezing and entanglement in a two-mode Bose-Einstein condensate with time-dependent Josephson-like coupling

TL;DR

This paper analytically investigates how time-dependent Josephson-like coupling affects quantum squeezing and entanglement in a two-mode Bose-Einstein condensate, revealing conditions for maximal entanglement and the effects of nonlinear interactions.

Contribution

It provides analytical expressions for squeezing and entanglement dynamics in TBEC with time-varying coupling, highlighting the role of nonlinear interactions and self-trapping states.

Findings

Maximal entanglement achievable with nonlinear interactions.

Greater squeezing observed without nonlinear interactions.

Potential for stable, macroscopic entangled states in TBEC.

Abstract

Dynamical evolution of quantum mechanical squeezing and entanglement in a two-mode Bose-Einstein condensate (TBEC) with an adiabatic, time-varying Raman coupling is studied by finding analytical expressions for these quantities. In particular, we study the entanglement between the atoms in the condensate as well as that between the two modes. The nature of the enhanced quantum correlations in TBEC is clarified by considering squeezing and entanglement both with and without the nonlinear interaction turned on; it is found that entanglement approaching maximal value can be achieved with the nonlinear interactions present. Somewhat counter-intuitively, greater squeezing is found in the absence of nonlinear interactions. This is due to the collapses and revivals of the TBEC quantum state induced by the nonlinear interactions. In addition, results involving the self-trapping phase state of TBEC indicate potential for creating a dynamically stable, macroscopic entangled quantum state which is relatively robust with respect to atom number fluctuations.