Ground-state properties of few dipolar bosons in a quasi-one-dimensional harmonic trap

TL;DR

This paper investigates the ground state of a few dipolar bosons in a quasi-one-dimensional trap, revealing three distinct regimes—weakly interacting, fermionized, and crystalline—using exact diagonalization, and analyzing their properties and transitions.

Contribution

It identifies and characterizes three interaction regimes of dipolar bosons in a quasi-1D trap, including the transition from a Tonks-Girardeau gas to a Wigner crystal, with detailed analysis of their properties.

Findings

Three regimes: delta-like, fermionized, and crystalline states.

Transition marked by increased interaction energy and altered momentum distribution.

Crystalline state shows properties similar to a fermionic system.

Abstract

We study the ground state of few bosons with repulsive dipole-dipole interaction in a quasi-one-dimensional harmonic trap by means of the exact diagonalization method. Up to three interaction regimes are found depending on the strength of the dipolar interaction and the ratio of transverse to axial oscillator lengths: a regime where the dipolar Bose gas resembles a system of weakly delta-interacting bosons, a second regime where the bosons are fermionized, and a third regime where the bosons form a Wigner crystal. In the first two regimes, the dipole-dipole potential can be replaced by a delta potential. In the crystalline state, the overlap between the localized wave packets is strongly reduced and all the properties of the boson system equal those of its fermionic counterpart. The transition from the Tonks-Girardeau gas to the solidlike state is accompanied by a rapid increase of the interaction energy and a considerable change of the momentum distribution, which we trace back to the different short-range correlations in the two interaction regimes.