Metastability in Coexisting Competing Orders

TL;DR

This paper investigates the dynamics of systems with two competing orders under ultrafast laser pulses, revealing metastable states and the influence of fluctuations, with implications for superconductors and cosmological models.

Contribution

It introduces a theoretical framework for understanding metastability in coexisting orders under nonequilibrium conditions, linking experimental observations to fluctuation effects.

Findings

Enhanced order parameter post-pump

Emergence of metastable states

Fluctuation effects on free energy landscape

Abstract

The dynamical phase transition of a system with two coexisting competing order parameters is studied using the time-dependent-Ginzburg-Landau framework. The dynamics are induced by parameters capturing the physics of driving the system with an ultrafast laser pulse. A remarkable enhancement of the order parameter with a smaller mean-field value following the pump and the emergence of an induced metastable state is investigated through analytical and numerical studies. The effect of order parameter fluctuations on the exploration of the nonequilibrium free energy landscape reveals important information about the impact of both thermal and nonthermal fluctuations on the dynamics of the metastable state. Our results provide an interpretation of previously unexplained ultrafast experiments on superconductors with competing charge density wave order. Our formalism is relevant across broad classes of out-of-equilibrium systems beyond the condensed matter context, such as the Kibble-Zurek cosmological model.