A density-functional approach to fermionization in the 1D Bose gas

TL;DR

This paper develops a time-dependent Kohn-Sham approach for 1D bosons with contact interactions, enabling the study of fermionization and the transition between strongly and weakly interacting regimes.

Contribution

It introduces a novel density-functional scheme based on spinor fermions to model fermionization in 1D Bose gases, especially near the Tonks-Girardeau limit.

Findings

Accurately describes ground-state properties across interaction regimes

Captures elementary excitation spectrum in the Tonks limit

Provides an intuitive picture of fermionization extent

Abstract

A time-dependent Kohn-Sham scheme for 1D bosons with contact interaction is derived based on a model of spinor fermions. This model is specifically designed for the study of the strong interaction regime close to the Tonks gas. It allows us to treat the transition from the strongly-interacting Tonks-Girardeau to the weakly-interacting quasicondensate regime and provides an intuitive picture of the extent of fermionization in the system. An adiabatic local-density approximation is devised for the study of time-dependent processes. This scheme is shown to yield not only accurate ground-state properties but also overall features of the elementary excitation spectrum, which is described exactly in the Tonks-gas limit.