Non-coaxial vortices in two-component Bose-Einstein condensates: Persistent precession and nutation

TL;DR

This paper demonstrates the existence of stable, non-coaxial vortex configurations in two-component Bose-Einstein condensates, exhibiting persistent precession and nutation dynamics akin to a rigid body, induced by sudden nonlinearity activation.

Contribution

It introduces a new class of robust, non-coaxial vortices in two-component BECs supported by all-repulsive interactions and characterizes their unique precession and nutation behaviors.

Findings

Non-coaxial vortices are supported in two-component BECs with all-repulsive interactions.

These vortices exhibit persistent precession and nutation dynamics.

The dynamics can be qualitatively modeled as a rigid body motion.

Abstract

It is demonstrated that a two-component Bose-Einstein condensate (BEC) with all-repulsive inter-atomic interactions loaded into a radially symmetric harmonic trap supports robust non-coaxial vortices with approximately orthogonal vortex lines in each of the components. These cross vortices are excited from the linear modes by a sudden switch-on of the nonlinearity (via Feshbach resonance) and are characterized by persistent dynamical regimes of precession with nutation, resembling the motion of a rigid body. The obtained dynamics can be understood qualitatively on the basis of a simple mechanical model.