Critical Behavior of Charge Density Waves Below Threshold: Numerical and Scaling Analysis

TL;DR

This paper investigates the critical behavior of pinned charge density waves near the sliding threshold using numerical simulations and scaling analysis, revealing diverging length scales and avalanche dynamics.

Contribution

It provides a detailed numerical and scaling analysis of the critical behavior of charge density waves below the sliding threshold, highlighting diverging correlation lengths and avalanche phenomena.

Findings

Polarizability diverges in 1D and 2D near threshold

A dominant diverging correlation length controls threshold distribution

Finite-size effects reveal cutoff sizes for avalanches

Abstract

The critical behavior of pinned charge density waves (CDW's) is studied as the threshold for sliding is approached. Using the Fukuyama-Lee-Rice Hamiltonian with relaxational dynamics, the polarization and linear response are calculated numerically. ... On the irreversible approach to threshold, the response due to avalanches triggered by local instabilities dominates the polarizability, which diverges in one and two dimensions. Characteristic diverging length scales are studied using finite-size scaling of the sample-to-sample variations of the threshold field in finite systems and finite-size effects in the linear polarizability and the irreversible polarization. A dominant diverging correlation length is found which controls the threshold field distribution, finite-size effects in the irreversible polarization, and a cutoff size for the avalanche size distribution. Our results are compared with those for related models and questions are raised concerning the relationship of the static critical behavior below threshold to the dynamic critical behavior in the sliding state above threshold.