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 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.
Role of the Vortex-Core Energy on the Berezinskii-Kosterlitz-Thouless Transition in Thin Films of NbN / Mondal, Mintu; Kumar, Sanjeev; Chand, Madhavi; Kamlapure, Anand; Saraswat, Garima; Seibold, G.; Benfatto, L.; Raychaudhuri, Pratap. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 107:21(2011). [10.1103/PhysRevLett.107.217003]
Role of the Vortex-Core Energy on the Berezinskii-Kosterlitz-Thouless Transition in Thin Films of NbN
Seibold G.;Benfatto L.;Raychaudhuri Pratap
2011
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 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
