Quantum magnetism in strongly interacting one-dimensional spinor Bose systems

TL;DR

This paper explores the magnetic properties of strongly interacting two-component bosonic systems in one dimension, revealing novel ferromagnetic and antiferromagnetic states that emerge in the strongly interacting regime.

Contribution

It introduces a theoretical analysis of two-component bosons with dominant inter-species interactions, uncovering new magnetic phases and energy spectra in one-dimensional quantum systems.

Findings

Ground states are spatially separated with ferromagnetic wave functions.

Excited states exhibit perfect antiferromagnetic ordering.

Energy levels are fractions of the harmonic oscillator quantum.

Abstract

Strongly interacting one-dimensional quantum systems often behave in a manner that is distinctly different from their higher-dimensional counterparts. When a particle attempts to move in a one-dimensional environment it will unavoidably have to interact and 'push' other particles in order to execute a pattern of motion, irrespective of whether the particles are fermions or bosons. A present frontier in both theory and experiment are mixed systems of different species and/or particles with multiple internal degrees of freedom. Here we consider trapped two-component bosons with short-range inter-species interactions much larger than their intra-species interactions and show that they have novel energetic and magnetic properties. In the strongly interacting regime, these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated ground states with manifestly ferromagnetic wave functions. Furthermore, we predict excited states that have perfect antiferromagnetic ordering. This holds for both balanced and imbalanced systems, and we show that it is a generic feature as one crosses from few- to many-body systems.