Resonant nucleation of spatio-temporal order via parametric modal amplification

TL;DR

This paper explores how parametric amplification triggers the emergence of spatio-temporal order, such as oscillons, and accelerates metastable state decay in nonequilibrium scalar field theories, revealing new mechanisms of resonant nucleation.

Contribution

It introduces a mechanism where parametric amplification induces order and rapid decay in scalar fields with double-well potentials, expanding understanding of nonequilibrium dynamics.

Findings

Oscillons emerge via synchronized parametric amplification.

Ordered structures act as bottlenecks for equipartition.

Decay rates can be significantly faster than homogeneous nucleation.

Abstract

We investigate, analytically and numerically, the emergence of spatio-temporal order in nonequilibrium scalar field theories. The onset of order is triggered by destabilizing interactions (DIs), which instantaneously change the interacting potential from a single to a double-well, tunable to be either degenerate (SDW) or nondegenerate (ADW). For the SDW case, we observe the emergence of spatio-temporal coherent structures known as oscillons. We show that this emergence is initially synchronized, the result of parametric amplification of the relevant oscillon modes. We also discuss how these ordered structures act as bottlenecks for equipartition. For ADW potentials, we show how the same parametric amplification mechanism may trigger the rapid decay of a metastable state. For a range of temperatures, the decay rates associated with this resonant nucleation can be orders of magnitude larger than those computed by homogeneous nucleation, with time-scales given by a simple power law, $\tau_{\rm RN}\sim[E_b/k_BT]^B$, where $B$ depends weakly on the temperature and $E_b/k_BT$ is the free-energy barrier of a critical fluctuation.