Terahertz thermal spectroscopy of a NbN superconductor

0367191 - FZÚ 2012 RIV US eng J - Journal Article
Tesař, Roman - Šindler, Michal - Il'in, K. - Koláček, Jan - Siegel, M. - Skrbek, L.
Terahertz thermal spectroscopy of a NbN superconductor.
Physical Review. B. Roč. 84, č. 13 (2011), 132506/1-132506/4. ISSN 1098-0121
R&D Projects: GA ČR(CZ) GAP204/11/0015; GA MŠMT(CZ) ME10069
Institutional research plan: CEZ:AV0Z10100521
Keywords : response to electromagnetic fields * optical properties * superconducting films * low-dimensional structures
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.691, year: 2011

We report far-infrared optical properties of a NbN superconductor. Transmission through a high-quality NbN film grown on a birefringent sapphire substrate above and below its superconducting transition down to the zero-temperature limit is measured at six different frequencies from 0.4 to 2.5 THz both above and below its optical gap. The experimental results agree with theoretical calculations developed based on utilization and extension of the BCS model of Zimmermann et al. [Physica C 183, 99 (1991)] applied for the NbN film. Full quantitative agreement over the entire ranges of temperature and frequencies is found based solely on the physical properties of this NbN film sample and on the parameters of an identical sapphire substrate as measured in time-domain spectroscopy experiments, without use of any additional fitting parameters.
Permanent Link: http://hdl.handle.net/11104/0201944