Excitations of attractive 1-D bosons: Binding vs. fermionization

TL;DR

This paper explores the behavior of few one-dimensional bosons under varying attractive interactions, identifying distinct classes of states including bound, fragmented, and fermionized states, with detailed correlation and spectral analysis.

Contribution

It introduces a comprehensive classification of stationary states in attractive 1D bosonic systems and analyzes their properties across the interaction spectrum.

Findings

Identification of three classes of states: N-body bound, fragmented bound, and fermionized gas-like states.

Analysis of two-body correlations and momentum spectra for each class.

Use of a soluble two-particle model to illustrate the state behaviors.

Abstract

The stationary states of few bosons in a one-dimensional harmonic trap are investigated throughout the crossover from weak to strongly attractive interactions. For sufficient attraction, three different classes of states emerge: (i) N-body bound states, (ii) bound states of smaller fragments, and (iii) gas-like states that fermionize, that is, map to ideal fermions in the limit of infinite attraction. The two-body correlations and momentum spectra characteristic of the three classes are discussed, and the results are illustrated using the soluble two-particle model.