Shards of Broken Symmetry: Topological Defects as Traces of the Phase Transition Dynamics

TL;DR

This paper explores how topological defects serve as indicators of phase transition dynamics, focusing on homogeneous second order transitions and comparing experimental results in helium systems with theoretical models.

Contribution

It provides a detailed analysis of topological defect formation during phase transitions, addressing discrepancies between experiments and theories, and discusses implications for various physical systems.

Findings

Discrepancies between 3He and 4He experimental results are analyzed.

The role of the Ginzburg regime in vortex density is considered and dismissed.

Differences between effective field theory and kinetic theory descriptions are discussed.

Abstract

We discuss the origin of topological defects in phase transitions and analyze their role as a "diagnostic tool" in the study of the non-equilibrium dynamics of symmetry breaking. Homogeneous second order phase transitions are the focus of our attention, but the same paradigm is applied to the cross-over and inhomogeneous transitions. The discrepancy between the experimental results in 3He and 4He is discussed in the light of recent numerical studies. The possible role of the Ginzburg regime in determining the vortex line density for the case of a quench in 4He is raised and tentatively dismissed. The difference in the anticipated origin of the dominant signal in the two (3He and 4He) cases is pointed out and the resulting consequences for the subsequent decay of vorticity are noted. The possibility of a significant discrepancy between the effective field theory and (quantum) kinetic theory descriptions of the order parameter is briefly touched upon, using atomic Bose-Einstein condensates as an example.