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arXiv · 0709.0709

One-dimensional resistive states in quasi-two-dimensional superconductors

M. Bell·A. Sergeev·V. Mitin·J. Bird·A. Verevkin·G. Gol'tsman
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Abstract

We investigate competition between one- and two-dimensional topological excitations - phase slips and vortices - in formation of resistive states in quasi-two-dimensional superconductors in a wide temperature range below the mean-field transition temperature $T_{C0}$. The widths $w$ = 100 nm of our ultrathin NbN samples is substantially larger than the Ginzburg-Landau coherence length $ξ$ = 4nm and the fluctuation resistivity above $T_{C0}$ has a two-dimensional character. However, our data shows that the resistivity below $T_{C0}$ is produced by one-dimensional excitations, - thermally activated phase slip strips (PSSs) overlapping the sample cross-section. We also determine the scaling phase diagram, which shows that even in wider samples the PSS contribution dominates over vortices in a substantial region of current/temperature variations. Measuring the resistivity within seven orders of magnitude, we find that the quantum phase slips can only be essential below this level.

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M. Bell, A. Sergeev, V. Mitin, J. Bird, A. Verevkin, G. Gol'tsman. 2007-09-05. One-dimensional resistive states in quasi-two-dimensional superconductors. https://doi.org/10.1103/physrevb.76.094521

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