Black soliton in a quasi-one-dimensional trapped fermion-fermion mixture

TL;DR

This paper investigates the formation and stability of black solitons in a quasi-one-dimensional degenerate fermion-fermion mixture using a mean-field-hydrodynamic model, combining variational and numerical methods.

Contribution

It introduces a mean-field-hydrodynamic approach to study black solitons in fermionic mixtures and demonstrates their stationary and vibrational properties.

Findings

Black solitons are the first stationary vibrational excitations in the system.

Black solitons can be generated and remain stable under perturbations.

The study provides a nonlinear continuation of harmonic oscillator vibrational states.

Abstract

Employing a time-dependent mean-field-hydrodynamic model we study the generation of black solitons in a degenerate fermion-fermion mixture in a cigar-shaped geometry using variational and numerical solutions. The black soliton is found to be the first stationary vibrational excitation of the system and is considered to be a nonlinear continuation of the vibrational excitation of the harmonic oscillator state. We illustrate the stationary nature of the black soliton, by studying different perturbations on it after its formation.