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arXiv · 1108.0912

Role of the vortex-core energy on the Beresinkii-Kosterlitz-Thouless transition in thin films of NbN

Mintu Mondal·Sanjeev Kumar·Madhavi Chand·Anand Kamlapure·Garima Saraswat·G. Seibold·L. Benfatto·Pratap Raychaudhuri
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Abstract

We analyze the occurrence of the Beresinkii-Kosterlitz-Thouless transition in thin films of NbN at various film thickness, by probing the effect of vortex fluctuations on the temperature dependence of the superfluid density below $T_{BKT}$ and of the resistivity above $T_{BKT}$. By direct comparison between the experimental data and the theory we show the crucial role played by the vortex-core energy in determining the characteristic signatures of the BKT physics, and we estimate its dependence on the disorder level. Our work provides a paradigmatic example of BKT physics in a quasi-two-dimensional superconductor.

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Mintu Mondal, Sanjeev Kumar, Madhavi Chand, Anand Kamlapure, Garima Saraswat, G. Seibold, L. Benfatto, Pratap Raychaudhuri. 2011-08-03. Role of the vortex-core energy on the Beresinkii-Kosterlitz-Thouless transition in thin films of NbN. https://doi.org/10.1103/physrevlett.107.217003

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