Nature of 3D Bose Gases near Resonance

TL;DR

This paper investigates the properties of 3D Bose gases near resonance, revealing an instability point where gases become strongly coupled to molecules, with implications for their energetics and metastability.

Contribution

It introduces a resummation approach to analyze the energetics of nearly fermionized Bose gases near resonance, identifying the critical scattering length for instability.

Findings

Onset instability at a critical scattering length

Maximum chemical potential near instability

Three-body force effects are a few percent

Abstract

In this paper, we explore the nature of three-dimensional Bose gases at large positive scattering lengths via resummation of dominating processes involving a minimum number of virtual atoms. We focus on the energetics of the nearly fermionized Bose gases beyond the usual dilute limit. We also find that an onset instability sets in at a critical scattering length, beyond which the near-resonance Bose gases become strongly coupled to molecules and lose the metastability. Near the point of instability, the chemical potential reaches a maximum, and the effect of the three-body forces can be estimated to be around a few percent.