Incoherent matter-wave solitons

TL;DR

This paper investigates how thermal clouds and condensate depletion influence matter-wave solitons in Bose-Einstein condensates, revealing collapse mechanisms and the formation of mixed matter-wave structures using advanced theoretical modeling.

Contribution

It introduces a detailed analysis of BEC soliton dynamics at finite temperature using TDHFB theory, highlighting collapse and splitting phenomena not previously characterized.

Findings

Collapse of BEC via atom pair emission

Splitting into two oppositely moving solitons

Solitary waves as mixtures of condensed and noncondensed particles

Abstract

The dynamics of matter-wave solitons in Bose-Einstein condensates (BEC) is considerably affected by the presence of a surrounding thermal cloud and by condensate depletion during its evolution. We analyze these aspects of BEC soliton dynamics, using time-dependent Hartree-Fock-Bogoliubov (TDHFB) theory. The condensate is initially prepared within a harmonic trap at finite temperature, and solitonic behavior is studied by subsequently propagating the TDHFB equations without confinement. Numerical results demonstrate the collapse of the BEC via collisional emission of atom pairs into the thermal cloud, resulting in splitting of the initial density into two solitonic structures with opposite momentum. Each one of these solitary matter waves is a mixture of condensed and noncondensed particles, constituting an analog of optical random-phase solitons.