Bose-Einstein-condensed gases with arbitrary strong interactions

TL;DR

This paper develops a theoretical framework to analyze Bose-Einstein-condensed gases across all interaction strengths, using a self-consistent mean-field approach that is conserving and gapless, applicable at zero temperature.

Contribution

It introduces a comprehensive method for studying strongly interacting Bose gases with a unified treatment across interaction regimes.

Findings

Validates the mean-field theory for a uniform Bose gas at zero temperature.

Provides a self-consistent, conserving, and gapless approach for arbitrary interaction strengths.

Lays groundwork for future experimental and theoretical studies of strongly interacting Bose systems.

Abstract

Bose-condensed gases are considered with an effective interaction strength varying in the whole range of the values between zero and infinity. The consideration is based on the usage of a representative statistical ensemble for Bose systems with broken global gauge symmetry. Practical calculations are illustrated for a uniform Bose gas at zero temperature, employing a self-consistent mean-field theory, which is both conserving and gapless.