Spontaneous symmetry breaking induced by interaction in linearly coupled binary Bose Einstein condensates

TL;DR

This paper investigates how linear coupling in a binary Bose-Einstein condensate can induce spontaneous symmetry breaking, leading to asymmetric ground states and phase transitions, with potential implications for quantum control.

Contribution

It demonstrates that Rabi coupling in a linearly coupled binary BEC promotes symmetry breaking and phase transitions, supported by numerical simulations of asymmetric ground states.

Findings

Linear coupling induces asymmetry in the BEC components

Symmetric and asymmetric ground states are identified

Rabi coupling promotes Josephson and SSB phases

Abstract

We analyze the spontaneous symmetry breaking (SSB) induced by one specific component of a linearly coupled binary Bose-Einstein condensate (BEC). The model is based on linearly coupled Schr\"odinger equations with cubic nonlinearity and with a double-well (DW) potential acting on only one of the atomic components. By numerical simulations, symmetric and asymmetric ground-states were obtained, and an induced asymmetry in the partner field was observed. In this sense, we properly demonstrated that the linear coupling mixing the two-field component (Rabi coupling) promotes the (in)balance between atomic species, as well as the appearance of the Josephson and SSB phases.