The Yrast Spectra of Weakly Interacting Bose-Einstein Condensates

TL;DR

This paper investigates the low-energy spectra of weakly interacting Bose-Einstein condensates, revealing new condensate phases and phase transitions linked to angular momentum distribution within the system.

Contribution

It introduces a novel analysis of condensate behavior, uncovering additional condensate types and phase transitions based on angular momentum partitioning.

Findings

Identification of two new condensate phases

Discovery of associated thermodynamic phase transitions

Analysis based on degrees of freedom in partition space

Abstract

The low energy quantal spectrum is considered as a function of the total angular momentum for a system of weakly interacting bosonic atoms held together by an external isotropic harmonic potential. It is found that besides the usual condensation into the lowest state of the oscillator, the system exhibits two additional kinds of condensate and associated thermodynamic phase transitions. These new phenomena are derived from the degrees of freedom of "partition space" which describes the multitude of different ways in which the angular momentum can be distributed among the atoms while remaining all the time in the lowest state of the oscillator.