Topological defects as relics of spontaneous symmetry breaking from black hole physics

TL;DR

This paper uses holographic duality to study the formation of vortices during symmetry breaking in a strongly coupled superconductor, confirming the Kibble-Zurek mechanism's predictions for defect density and correlations.

Contribution

It provides a first-principles holographic analysis of topological defect formation in strongly coupled systems without quasiparticles, specifically in a (2+1)-D superconductor.

Findings

Magnetic fluxons emerge as quantized vortices post-transition.

Vortex density depends on quench time as predicted by Kibble-Zurek.

Vortex-vortex correlations match theoretical expectations.

Abstract

Formation and evolution of topological defects in course of non-equilibrium symmetry breaking phase transitions is of wide interest in many areas of physics, from cosmology through condensed matter to low temperature physics. Its study in strongly coupled systems, in absence of quasiparticles, is especially challenging. We investigate breaking of U(1) symmetry and the resulting spontaneous formation of vortices in a $(2+1)$-dimensional holographic superconductor employing gauge/gravity duality, a `first-principles' approach to study strongly coupled systems. Magnetic fluxons with quantized fluxes are seen emerging in the post-transition superconducting phase. As expected in type II superconductors, they are trapped in the cores of the order parameter vortices. The dependence of the density of these topological defects on the quench time, the dispersion of the typical winding numbers in the superconductor, and the vortex-vortex correlations are consistent with predictions of the Kibble-Zurek mechanism.