Rotational relaxation in Brownian rotors with frustrated interactions on a square lattice

TL;DR

This paper investigates the equilibrium rotational relaxation of Brownian rotors modeled by a frustrated XY system on a square lattice, revealing complex dynamics similar to supercooled liquids, including a crossover from Arrhenius to non-Arrhenius behavior.

Contribution

It provides the first simulation-based analysis of rotational relaxation in frustrated XY models, highlighting the connection to glassy dynamics and energy landscape effects.

Findings

Observation of two-step relaxation dynamics.

Identification of a dynamic crossover from Arrhenius to non-Arrhenius behavior.

Evidence of caging and thermal activation mechanisms.

Abstract

We present simulation results on the equilibrium relaxation of Brownian planar rotors based on a uniformly frustrated XY model on a square lattice. The rotational relaxation exhibits typical dynamic features of fragile supercooled liquids including the two-step relaxation. We observe a dynamic cross-over from high temperature regime with Arrhenius behavior to low temperaure regime with temperature-dependent activation energy. A consistent picture for the observed slow dynamics can be given in terms of caging effect and thermal activation across potential barriers in the energy landscapes.