Exact results of the ground state and excitation properties of a two-component interacting Bose system

TL;DR

This paper provides exact analytical and numerical results for the ground state and excitations of a one-dimensional two-component Bose system with repulsive interactions, revealing an isospin-ferromagnetic ground state and three elementary excitations.

Contribution

It offers the first exact solutions for the ground state and low-lying excitations of a 1D two-component Bose system with SU(2) symmetry using Bethe-ansatz methods.

Findings

Ground state is isospin-ferromagnetic.

Excitations include holons, antiholons, and isospinons.

Isospinon forms a triplet coupled to the ferromagnetic background.

Abstract

We study a one-dimensional Bose system with repulsive delta-function interaction in the presence of an SU(2) intrinsic degree of freedom on the basis of the coordinate Bethe-ansatz. The ground state and the low-lying excitations are determined by both numerical and analytical methods. It is shown that the ground state is an isospin-ferromagnetic state, and the excitations are composed of three elementary particles: holons, antiholons, and isospinons. The isospinon is a triplet coupled to the "ferromagnetic" background anti-parallelly.