Cerenkov-like radiation in a binary Schr{\"o}dinger flow past an obstacle

TL;DR

This paper investigates the dynamics of two coupled Bose-Einstein condensates when an obstacle moves through them, revealing different regimes of structure formation depending on the speeds of sound in each component.

Contribution

It introduces a detailed analysis of the three dynamical regimes in binary condensates, including the nucleation of novel structures like dark-antidark solitons and vortex-lumps.

Findings

No structures nucleate when both components are subcritical.

Dark solitons and vortices form when both are supercritical.

Dark-antidark solitons and vortex-lumps appear in intermediate regimes.

Abstract

We consider the dynamics of two coupled miscible Bose-Einstein condensates, when an obstacle is dragged through them. The existence of two different speeds of sound provides the possibility for three dynamical regimes: when both components are subcritical, we do not observe nucleation of coherent structures; when both components are supercritical they both form dark solitons in one dimension (1D) and vortices or rotating vortex dipoles in two dimensions (2D); in the intermediate regime, we observe the nucleation of a structure in the form of a dark-antidark soliton in 1D; subcritical component; the 2D analog of such a structure, a vortex-lump, is also observed.