Generation of dark-bright soliton trains in superfluid-superfluid counterflow

TL;DR

This paper reports the first experimental observation of dark-bright soliton trains generated by counterflow in a two-component Bose-Einstein condensate, supported by numerical simulations and theoretical analysis.

Contribution

It provides the first experimental evidence and theoretical interpretation of dark-bright soliton trains formed in superfluid counterflow within a Bose-Einstein condensate.

Findings

First experimental observation of dark-bright soliton trains

Counterflow induces modulational instability in superfluids

Numerical simulations support experimental results

Abstract

The dynamics of two penetrating superfluids exhibit an intriguing variety of nonlinear effects. Using two distinguishable components of a Bose-Einstein condensate, we investigate the counterflow of two superfluids in a narrow channel. We present the first experimental observation of trains of dark-bright solitons generated by the counterflow. Our observations are theoretically interpreted by three-dimensional numerical simulations for the coupled Gross-Pitaevskii (GP) equations and the analysis of a jump in the two relatively flowing components' densities. Counterflow induced modulational instability for this miscible system is identified as the central process in the dynamics.