Path integral molecular dynamics for thermodynamics and Green's function of ultracold spinor bosons

TL;DR

This paper develops a path integral molecular dynamics method to simulate thermodynamics, Green's functions, and momentum distributions of two-component ultracold spinor bosons, providing insights into their behavior under varying interactions.

Contribution

It introduces a novel simulation approach for spinor bosons, extending previous methods to include Green's functions and momentum distributions in three dimensions.

Findings

Heat capacity shows a bump for noninteracting bosons.

Increasing repulsive interactions suppress the heat capacity bump.

Simulation results are relevant for ultracold bosons in optical lattices.

Abstract

Most recently, the path integral molecular dynamics has been successfully used to consider the thermodynamics of single-component identical bosons and fermions. In this work, the path integral molecular dynamics is developed to simulate the thermodynamics, Green's function and momentum distribution of two-component bosons in three dimensions. As an example of our general method, we consider the thermodynamics of up to sixteen bosons in a three-dimensional harmonic trap. For noninteracting spinor bosons, our simulation shows a bump in the heat capacity. As the repulsive interaction strength increases, however, we find the gradual disappearance of the bump in the heat capacity. We believe this simulation result can be tested by ultracold spinor bosons with optical lattices and magnetic-field Feshbach resonance to tune the inter-particle interaction. We also calculate Green's function and momentum distribution of spinor bosons. Our work facilitates the exact numerical simulation of spinor bosons, whose property is one of the major problems in ultracold Bose gases.