Breathers on Quantized Superfluid Vortices

TL;DR

This paper investigates breather solutions on quantized superfluid vortices, demonstrating their emergence, stability, and implications for superfluid turbulence across different physical models.

Contribution

It establishes a connection between breather solutions and vortex dynamics, showing their relevance in superfluid turbulence and other physical systems.

Findings

Breather solutions lead to large amplitude, localized perturbations on vortices.

Numerical simulations confirm breather attributes in Biot-Savart and Gross-Pitaevskii models.

Breathers can induce vortex self-reconnections, impacting turbulence dynamics.

Abstract

We consider the propagation of breathers along a quantised superfluid vortex. Using the correspondence between the local induction approximation (LIA) and the nonlinear Schr\"odinger equation, we identify a set of initial conditions corresponding to breather solutions of vortex motion governed by the LIA. These initial conditions, which give rise to a long-wavelength modulational instability, result in the emergence of large amplitude perturbations that are localised in both space and time. The emergent structures on the vortex filament are analogous to loop solitons. Although the breather solutions we study are exact solutions of the LIA equations, we demonstrate through full numerical simulations that their key emergent attributes carry over to vortex dynamics governed by the Biot-Savart law and to quantized vortices described by the Gross-Pitaevskii equation. The breather excitations can lead to self-reconnections, a mechanism that can play an important role within the cross-over range of scales in superfluid turbulence. Moreover, the observation of breather solutions on vortices in a field model suggests that these solutions are expected to arise in a wide range of other physical contexts from classical vortices to cosmological strings.