Self-trapping of Fermi and Bose gases under spatially modulated repulsive nonlinearity and transverse confinement

TL;DR

This paper demonstrates the creation of self-localized ground states in Fermi and Bose gases with spatially varying repulsive interactions and transverse confinement, using the TF-vW density functional framework.

Contribution

It introduces a novel approach to generate self-trapped states in Fermi and Bose gases with spatially modulated repulsive nonlinearities and analyzes the negligible role of the vW correction.

Findings

Self-localized states can be formed with spatially growing repulsive interactions.

The vW correction is nearly negligible compared to the TF approximation.

Ground state properties are characterized under various transverse confinements.

Abstract

We show that self-localized ground states can be created in the spin-balanced gas of fermions with repulsion between the spin components, whose strength grows from the center to periphery, in combination with the harmonic-oscillator (HO) trapping potential acting in one or two transverse directions. We also consider the ground state in the non-interacting Fermi gas under the action of the spatially growing tightness of the one- or two-dimensional (1D or 2D) HO confinement. These settings are considered in the framework of the Thomas-Fermi-von Weizsacker (TF-vW) density functional. It is found that the vW correction to the simple TF approximation (the gradient term) is nearly negligible in all situations. The properties of the ground state under the action of the 2D and 1D HO confinement with the tightness growing in the transverse directions is investigated too for the Bose-Einstein condensate (BEC) with the self-repulsive nonlinearity.