Thermal Rounding of the Charge Density Wave Depinning Transition

TL;DR

This paper investigates how thermal noise causes the charge density wave depinning transition to become smoother, revealing a power-law relationship between creep velocity and temperature, supported by numerical and experimental consistency.

Contribution

It introduces a theoretical prediction of power-law thermal rounding of the depinning transition, confirmed by numerical simulations and aligned with experimental observations.

Findings

Creep velocity follows a power-law dependence on temperature at the depinning threshold.

Numerical computations support the theoretical prediction.

Experimental data are consistent with the predicted thermal rounding magnitude.

Abstract

The rounding of the charge density wave depinning transition by thermal noise is examined. Hops by localized modes over small barriers trigger ``avalanches'', resulting in a creep velocity much larger than that expected from comparing thermal energies with typical barriers. For a field equal to the $T=0$ depinning field, the creep velocity is predicted to have a {\em power-law} dependence on the temperature $T$; numerical computations confirm this result. The predicted order of magnitude of the thermal rounding of the depinning transition is consistent with rounding seen in experiment.