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Nonequilibrium Campbell length: probing the vortex pinning potential

R. Prozorov·R. W. Giannetta·T. Tamegai·P. Guptasarma·D. G. Hinks
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Abstract

The $AC$ magnetic penetration depth $λ(T,H,j)$ was measured in presence of a macroscopic $DC$ (Bean) supercurrent, $j$. In single crystal BSCCO below approximately 28 K, $λ(T,H,j)$ exhibits thermal hysteresis. The irreversibility arises from a shift of the vortex position within its pinning well as $j$ changes. It is demonstrated that below a new irreversibility temperature, the nonequilibrium Campbell length depends upon the ratio $j/j_c$. $λ(T,H,j)$ {\it increases} with $j/j_c$ as expected for a non-parabolic potential well whose curvature {\it decreases} with the displacement. Qualitatively similar results are observed in other high-$T_{c}$ and conventional superconductors.

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R. Prozorov, R. W. Giannetta, T. Tamegai, P. Guptasarma, D. G. Hinks. 2000-04-08. Nonequilibrium Campbell length: probing the vortex pinning potential. https://arxiv.org/abs/cond-mat/0004122

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