Interferencing in coupled Bose-Einstein condensates

TL;DR

This paper presents an exactly solvable model of two coupled Bose-Einstein condensates, analyzing their equilibrium states, fluctuations, and dynamics, including collapse and revival phenomena, with implications for quantum coherence and symmetry breaking.

Contribution

It introduces an exactly solvable model of coupled BECs, explicitly characterizing their equilibrium states, fluctuations, and dynamical behavior, including phase-current relations.

Findings

Explicit equilibrium states showing condensation and symmetry breaking

Identification of quantum canonical pairs among fluctuation operators

Solution of dynamics revealing collapse and revival phenomena

Abstract

We consider an exactly soluble model of two Bose-Einstein condensates with a Josephson-type of coupling. Its equilibrium states are explicitly found showing condensation and spontaneously broken gauge symmetry. It is proved that the total number and total phase fluctuation operators, as well as the relative number and relative current fluctuation operators form both a quantum canonical pair. The exact relation between the relative current and phase fluctuation operators is established. Also the dynamics of these operators is solved showing the collapse and revival phenomenon.