Atomic Bose Gas with Negative Scattering Length

TL;DR

This paper analyzes a dilute atomic Bose gas with negative scattering length, revealing that quantum degeneracy induces phase transitions which are replaced by a first-order transition, impacting experiments with lithium and cesium gases.

Contribution

It derives the equation of state for a Bose gas with negative scattering length and predicts the preemption of continuous phase transitions by a first-order transition.

Findings

Quantum degeneracy induces phase transitions in the gas.

First-order gas-liquid or gas-solid transition preempts continuous transitions.

Implications for experiments with lithium and cesium gases.

Abstract

We derive the equation of state of a dilute atomic Bose gas with an interatomic interaction that has a negative scattering length and argue that two continuous phase transitions, occuring in the gas due to quantum degeneracy effects, are preempted by a first-order gas-liquid or gas-solid transition depending on the details of the interaction potential. We also discuss the consequences of this result for future experiments with magnetically trapped spin-polarized atomic gasses such as lithium and cesium.