Role of the Vortex-Core Energy on the Berezinskii-Kosterlitz-Thouless Transition in Thin Films of NbN
Abstract
We analyze the occurrence of the Berezinskii-Kosterlitz-Thouless (BKT) 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 TBKT and of the resistivity above TBKT. 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.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 2011
- DOI:
- arXiv:
- arXiv:1108.0912
- Bibcode:
- 2011PhRvL.107u7003M
- Keywords:
-
- 74.40.-n;
- 74.62.En;
- 74.70.Ad;
- 74.78.-w;
- Metals;
- alloys and binary compounds;
- Superconducting films and low-dimensional structures;
- Condensed Matter - Superconductivity;
- Condensed Matter - Disordered Systems and Neural Networks;
- Condensed Matter - Statistical Mechanics
- E-Print:
- Phys. Rev. Lett. 107, 217003 (2011)