Symmetry-breaking self-consistent quantum many-body structure of high-lying macroscopic self-trapped and superposition states of the gaseous double-well BEC

TL;DR

This paper investigates the complex many-body quantum states of a double-well Bose-Einstein condensate, revealing how symmetry-breaking influences the energy and spatial properties of self-trapped and superposition states.

Contribution

It introduces a multiconfigurational self-consistent field approach to analyze high-lying excited states, highlighting the role of symmetry breaking and correlations in these states.

Findings

Superposition states are energetically favored over self-trapped states.

Distinct spatial density profiles characterize different excited states.

Symmetry breaking and correlations critically influence the many-body structure.

Abstract

The many-body structure of high-lying excited states, including macroscopic quantum superpositions, of the gaseous double-well BEC is presented within the context of a multiconfigurational bosonic self-consistent field theory based upon underlying symmetry-broken one-body wave functions. To better understand our initial results, a model is constructed in the extreme Fock state limit, in which macroscopic quantum self-trapped and superposition states emerge in the many-body spectrum, striking a delicate balance between the degree of symmetry breaking, the effects of the condensate's mean field, and that of atomic correlation. It is found that, in general, the superposition state lies energetically below its related self-trapped counterpart. Furthermore, noticeably different spatial density profiles are associated with each type of excited state.