Inhomogeneous Structures in Holographic Superfluids: II. Vortices

TL;DR

This paper investigates vortex solutions in a holographic superfluid model, analyzing core charge density, critical velocity, and potential phase transitions, providing insights into superfluid vortex behavior via holography.

Contribution

It introduces detailed holographic vortex solutions in a superfluid context, examining length scales, core charge density, and phase transition possibilities, extending prior holographic superfluid studies.

Findings

Charge density inside vortex cores varies with temperature and chemical potential.

Critical superfluid velocity depends on temperature and aligns with the Landau criterion.

Discussion of a possible BKT vortex confinement-deconfinement transition.

Abstract

We study vortex solutions in a holographic model of Herzog, Hartnoll, and Horowitz, with a vanishing external magnetic field on the boundary, as is appropriate for vortices in a superfluid. We study relevant length scales related to the vortices and how the charge density inside the core of the vortex behaves as a function of temperature or chemical potential. We extract the critical superfluid velocity from the vortex solutions, study how it behaves as a function of the temperature, and compare it to earlier studies and to the Landau criterion. We also comment on the possibility of a Berezinskii-Kosterlitz-Thouless vortex confinement-deconfinement transition.