Non-Equilibrium Origin of Native Ring Anisotropy in Amorphous Systems

TL;DR

This paper introduces a stochastic model called Indistinguishable Simulated Folding (ISF) that explains the universal structural anisotropy in amorphous networks as a non-equilibrium process during annealing quenching, independent of specific interactions.

Contribution

The paper presents the ISF model, a Markov process-based simulation framework that captures the stochastic origin of native ring anisotropy in amorphous systems without detailed molecular dynamics.

Findings

ISF effectively reproduces universal anisotropy features.

Logarithm of anisotropy measures follows a skewed distribution.

Model parameters relate to physical thermally induced structural changes.

Abstract

Native ring structures within amorphous networks play a critical role in determining structural and optical properties, in part due to their ability to host dopants such as rare earth ions in silicate systems. In this work, we demonstrate that the universal features of structural anisotropy in amorphous networks can be efficiently simulated using a model based on stochastically deformed, edge sharing N member native ring structures. This model isolates and characterizes the structural anisotropy generated during the annealing quenching process that is independent of any constituent specific interactions. We refer to this computational framework as Indistinguishable Simulated Folding (ISF), a stochastic process that mimics a simulated annealing quenching procedure. Formulated as a Markov process, ISF is governed by two physically meaningful parameters: the number of Markov steps, representing the mean duration of each ring folding event, and the stochastic deformation magnitude, which quantifies thermally induced structural changes per event. Furthermore, we show that the logarithm of any positive valued anisotropy measure generated by ISF is a skewed random variable, reflecting the growing entropy production rate during the Markov evolution. ISF provides both a conceptual framework for understanding the universal stochastic origin of structural anisotropy in amorphous networks and a practical tool for simulating constituent independent features, without requiring full scale molecular dynamics simulations.