Flux quanta driven by high-density currents in low-impurity V3Si and LuNi2B2C: free flux flow and flux-core size effect

Abstract

High density direct currents (DC) are used to drive flux quanta via the Lorentz force towards a highly ordered "free flux flow" (FFF) dynamic state, made possible by the weak-pinning environment of high-quality, single-crystal samples of two low-Tc superconducting compounds, V3Si and LuNi2B2C. We report the effect of the magnetic field-dependent fluxon core size on flux flow resistivity rho_f. Much progress has been made in minimizing the technical challenges associated with the use of high currents. Attainment of a FFF phase is indicated by the saturation at highest currents of flux-flow dissipation levels that are well below the normal state resistance and have field-dependent values. The field dependence of the corresponding rho_f is shown to be consistent with a prediction based on a model for the decrease of flux core size at higher fields in weak-coupling BCS s-wave materials.

arXiv commentMore empirical treatment of the magnetoresistive correction of V3Si data by additional measurement and analysis (involving two new coauthors, Favreau and Henderson). End result is the same, making for a stronger manuscript

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Cited by in corpus (2)

• Evaluating free flux flow in low-pinning molybdenum-germanium superconducting films
• Vortex motion and flux-flow resistivity in dirty multiband superconductors