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Elastic String in a Random Potential

M. Dong·M. C. Marchetti·A. Alan Middleton·V. Vinokur
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Abstract

We have studied numerically the dynamics of a directed elastic string in a two-dimensional array of quenched random impurities. The string is driven by a constant transverse force and thermal fluctuations are neglected. There is a transition from pinned to unpinned behavior at a critical value $F_T$ of the driving force. At the transition the average string velocity scales with the driving force. The scaling is equally well described by a power law $v_d\sim (F-F_T)^ζ$, with $ζ=0.24\pm0.1$, or by a logarithm, $v_d\sim1/\ln(F-F_T)$. The divergence of the velocity-velocity correlation length at threshold is characterized by an exponent $ν=1.05\pm0.1$.

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M. Dong, M. C. Marchetti, A. Alan Middleton, V. Vinokur. 1992-05-20. Elastic String in a Random Potential. https://doi.org/10.1103/physrevlett.70.662

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