Spectral functions of strongly interacting isospin-1/2 bosons in one dimension

TL;DR

This paper investigates the low-energy spectral properties of strongly interacting one-dimensional isospin-1/2 bosons, revealing their spectrum comprises acoustic density waves and ferromagnetic spin excitations, with computed spectral functions.

Contribution

It introduces an effective ferromagnetic spin chain model for describing spin excitations in strongly interacting 1D bosons and computes their spectral functions.

Findings

Spectral functions of the system are explicitly calculated.

The low-energy spectrum includes acoustic density waves and ferromagnetic spin excitations.

The effective model accurately captures the system's spectral properties.

Abstract

We study a system of one-dimensional (iso)spin-1/2 bosons in the regime of strong repulsive interactions. We argue that the low-energy spectrum of the system consists of acoustic density waves and the spin excitations described by an effective ferromagnetic spin chain with a small exchange constant J. We use this description to compute the dynamic spin structure factor and the spectral functions of the system.