Dynamics of a Vortex Dipole in a Holographic Superfluid

TL;DR

This paper uses holographic simulations to analyze vortex-anti-vortex dynamics in a strongly coupled superfluid, revealing universal trajectories and temperature-dependent behaviors.

Contribution

It introduces a high-precision tracking algorithm for vortex trajectories in holographic superfluids, enabling detailed analysis of their universal motion and temperature effects.

Findings

Vortices follow universal trajectories regardless of initial separation.

Early-time motion shows artifacts from numerical initialization.

Vortex dynamics depend on the superfluid's temperature.

Abstract

We use holography to investigate the dynamics of a vortex-anti-vortex dipole in a strongly coupled superfluid in 2+1 dimensions. The system is evaluated in numerical real-time simulations in order to study the evolution of the vortices as they approach and eventually annihilate each other. A tracking algorithm with sub-plaquette resolution is introduced which permits a high-precision determination of the vortex trajectories. With the increased precision of the trajectories it becomes possible to directly compute the vortex velocities and accelerations. We find that in the holographic superfluid the vortices follow universal trajectories independent of their initial separation, indicating that a vortex-anti-vortex pair is fully characterized by its separation. Subtle non-universal effects in the vortex motion at early times of the evolution can be fully attributed to artifacts due to the numerical initialization of the vortices. We also study the dependence of the dynamics on the temperature of the superfluid.