Thermal rounding of the charge-density-wave depinning transition.

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 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.