Article

# Thermal rounding of the depinning transition

07/2007; DOI:doi:10.1209/0295-5075/81/26005
Source: arXiv

ABSTRACT We study thermal effects at the depinning transition by numerical simulations of driven one-dimensional elastic interfaces in a disordered medium. We find that the velocity of the interface, evaluated at the critical depinning force, can be correctly described with the power law $v\sim T^\psi$, where $\psi$ is the thermal exponent. Using the sample-dependent value of the critical force, we precisely evaluate the value of $\psi$ directly from the temperature dependence of the velocity, obtaining the value $\psi = 0.15 \pm 0.01$. By measuring the structure factor of the interface we show that both the thermally-rounded and the T=0 depinning, display the same large-scale geometry, described by an identical divergence of a characteristic length with the velocity $\xi \propto v^{-\nu/\beta}$, where $\nu$ and $\beta$ are respectively the T=0 correlation and depinning exponents. We discuss the comparison of our results with previous estimates of the thermal exponent and the direct consequences for recent experiments on magnetic domain wall motion in ferromagnetic thin films. Comment: 6 pages, 3 figures

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##### Article:Disordered Elastic Systems and One-Dimensional Interfaces
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ABSTRACT: We briefly introduce the generic framework of Disordered Elastic Systems (DES), giving a short `recipe' of a DES modeling and presenting the quantities of interest in order to probe the static and dynamical disorder-induced properties of such systems. We then focus on a particular low-dimensional DES, namely the one-dimensional interface in short-ranged elasticity and short-ranged quenched disorder. Illustrating different elements given in the introductory sections, we discuss specifically the consequences of the interplay between a finite temperature T>0 and a finite interface width \xi>0 on the static geometrical fluctuations at different lengthscales, and the implications on the quasistatic dynamics.
11/2011;

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29 Jan 2013

### Keywords

characteristic length

critical depinning force

critical force

depinning exponents

depinning transition

direct consequences

disordered medium

ferromagnetic thin films

large-scale geometry

magnetic domain wall motion

numerical simulations

one-dimensional elastic interfaces

power law $v\sim T^\psi$

previous estimates

structure factor

temperature dependence