Quench dynamics and scaling laws in topological nodal loop semimetals

We employ quench dynamics as an effective tool to probe different universality classes of topological phase transitions. Specifically, we study a model encompassing both Dirac-like and nodal loop criticalities. Examining the Kibble-Zurek scaling of topological defect density, we discover that the scaling exponent is reduced in the presence of extended nodal loop gap closures. For a quench through a multicritical point, we also unveil a path-dependent crossover between two sets of critical exponents. Bloch state tomography finally reveals additional differences in the defect trajectories for sudden quenches. While the Dirac transition permits a static trajectory under specific initial conditions, we find that the underlying nodal loop leads to complex time-dependent trajectories in general. In the presence of a nodal loop, we generically find a mismatch between the momentum modes where topological defects are generated and where dynamical quantum phase transitions occur. We also find notable exceptions where this correspondence breaks down completely.

Automated summary

This article employs quench dynamics to study different universality classes of topological phase transitions. The research reveals that the scaling exponent of topological defect density decreases in the presence of nodal loop gap closures. Additionally, a path-dependent crossover between two sets of critical exponents is discovered during a quench through a multicritical point. Bloch state tomography uncovers differences in defect trajectories for sudden quenches. It is found that while Dirac transition allows for a static trajectory under specific initial conditions, the underlying nodal loop leads to complex time-dependent trajectories in general. Notably, a mismatch is observed between the momentum modes where topological defects are generated and where dynamical quantum phase transitions occur in the presence of a nodal loop, although there are exceptions where this correspondence breaks down completely.