Quantum and thermal effects in dark soliton formation and dynamics in a 1D Bose gas

TL;DR

This paper investigates how quantum and thermal fluctuations influence the formation, stability, and dynamics of dark solitons in a 1D Bose gas, revealing fluctuations lower soliton speeds and induce instabilities.

Contribution

It introduces a numerical approach combining the truncated Wigner approximation with a quasi-condensate model to study fluctuation effects on dark solitons in 1D Bose gases.

Findings

Quantum and thermal fluctuations lower soliton speeds.

Fluctuations seed instabilities and soliton interactions.

Solitons can split or disappear due to fluctuations.

Abstract

We numerically study the imprinting and dynamics of dark solitons in a bosonic atomic gas in a tightly-confined one-dimensional harmonic trap both with and without an optical lattice. Quantum and thermal fluctuations are synthesized within the truncated Wigner approximation in the quasi-condensate description. We track the soliton coordinates and calculate position and velocity uncertainties. We find that the phase fluctuations {\em lower} the classically predicted soliton speed and seed instabilities. Individual runs show interactions of solitons with sound waves, splitting and disappearing solitons.