Symmetry-Breaking and Symmetry-Restoring Dynamics of a Mixture of Bose-Einstein Condensates in a Double Well

TL;DR

This paper investigates the nonlinear tunneling dynamics of a binary Bose-Einstein condensate mixture in a double well, revealing new swapping modes that restore symmetry and coexist with symmetry-breaking self-trapping phases.

Contribution

It introduces a new class of swapping modes in binary BEC mixtures that preserve symmetry, contrasting with known symmetry-breaking self-trapping solutions.

Findings

Discovery of swapping modes that restore symmetry in BEC mixtures

Identification of coexistence of symmetry-breaking and symmetry-restoring phases

Potential for experimental control of these phenomena in BEC systems

Abstract

We study the coherent nonlinear tunneling dynamics of a binary mixture of Bose-Einstein condensates in a double-well potential. We demonstrate the existence of a new type of mode associated with the "swapping" of the two species in the two wells of the potential. In contrast to the symmetry breaking macroscopic quantum self-trapping (MQST) solutions, the swapping modes correspond to the tunneling dynamics that preserves the symmetry of the double well potential. As a consequence of two distinct types of broken symmetry MQST phases where the two species localize in the different potential welils or coexist in the same well, the corresponding symmetry restoring swapping modes result in dynamics where the the two species either avoid or chase each other. In view of the possibility to control the interaction between the species, the binary mixture offers a very robust system to observe these novel effects as well as the phenomena of Josephson oscillations and pi-modes