Quantum phase transitions in an interacting atom-molecule boson model

TL;DR

This paper investigates quantum phase transitions in a model of interacting bosonic atoms and molecules, identifying a boundary line between molecular and mixed phases using classical and quantum analyses.

Contribution

It introduces a detailed analysis of phase boundaries in an atom-molecule boson model, combining classical and quantum methods to characterize phase transitions.

Findings

Identified a threshold coupling line separating phases.

Provided evidence linking the line to a boundary in the ground-state phase diagram.

Used energy gap, entanglement entropy, and fidelity as indicators.

Abstract

We study the quantum phase transitions of a model that describes the interconversion of interacting bosonic atoms and molecules. Using a classical analysis, we identify a threshold coupling line separating a molecular phase and a mixed phase. Through studies of the energy gap, von Neumann entanglement entropy, and fidelity, we give evidence that this line is associated to a boundary line in the ground-state phase diagram of the quantum system.