Temporal Dark Solitons in Nonuniform Bose-Einstein Condensates

TL;DR

This paper analyzes the behavior and properties of temporal dark solitons in nonuniform Bose-Einstein condensates, providing analytical, numerical, and simulation results that relate to experimental observations.

Contribution

It introduces an analytical expression for dark solitons in nonuniform condensates and demonstrates their propagation properties through numerical simulations.

Findings

Analytical expression for dark solitons under slow variation

Numerical validation of soliton propagation properties

Simulation linking dark solitons to experimental observations

Abstract

We discuss temporal dark solitons in confined nonuniform Bose condensates. As a kind of localized high excitation, these solitons can be viewed as macroscopic quasiparticles, having relative motion to the background condensate. We get an analytic expression for one dark soliton under a slowly varying approximation and discuss its special propagation properties in a nonuniform condensate, then we numerically prove that this approximation is reasonable and this kind of soliton exhibits their propagation properties in the nonuniform condensate. Finally, we simulate the generation of dark-soliton-like pulses in the condensate, and indicate that the excitation experiment, done by Ketterle and co-workers [Phys. Rev. Lett. 79, 553 (1997)], can also be interpreted in terms of temporal dark soliton.