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Melting of Flux Lines in an Alternating Parallel Current

Mohammad Kohandel·Mehran Kardar
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Abstract

We use a Langevin equation to examine the dynamics and fluctuations of a flux line (FL) in the presence of an {\it alternating longitudinal current} $J_{\parallel}(ω)$. The magnus and dissipative forces are equated to those resulting from line tension, confinement in a harmonic cage by neighboring FLs, parallel current, and noise. The resulting mean-square FL fluctuations are calculated {\it exactly}, and a Lindemann criterion is then used to obtain a nonequilibrium `phase diagram' as a function of the magnitude and frequency of $J_{\parallel}(ω)$. For zero frequency, the melting temperature of the mixed phase (a lattice, or the putative "Bose" or "Bragg Glass") vanishes at a limiting current. However, for any finite frequency, there is a non-zero melting temperature.

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Mohammad Kohandel, Mehran Kardar. 1998-08-15. Melting of Flux Lines in an Alternating Parallel Current. https://doi.org/10.1103/physrevb.59.9637

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