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Title: Superconducting energy scales and anomalous dissipative conductivity in thin films of molybdenum nitride

Abstract

We report investigations of molybdenum nitride (MoN) thin films with different thickness and disorder and with superconducting transition temperature 9.89K >= T-c >= 2.78 K. Using terahertz frequency-domain spectroscopy we explore the normal and superconducting charge carrier dynamics for frequencies covering the range from 3 to 38 cm(-1) (0.1 to 1.1 THz). The superconducting energy scales, i.e., the critical temperature T-c, the pairing energy Delta, and the superfluid stiffness J, and the superfluid density n(s) can be well described within the Bardeen-Cooper-Schrieffer theory for conventional superconductors. At the same time, we find an anomalously large dissipative conductivity, which cannot be explained by thermally excited quasiparticles, but rather by a temperature-dependent normal-conducting fraction, persisting deep into the superconducting state. Our results on this disordered system constrain the regime, where discernible effects stemming from the disorder-induced superconductor-insulator transition possibly become relevant, to MoN films with a transition temperature lower than at least 2.78 K.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1375921
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 94; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Simmendinger, Julian, Pracht, Uwe S., Daschke, Lena, Proslier, Thomas, Klug, Jeffrey A., Dressel, Martin, and Scheffler, Marc. Superconducting energy scales and anomalous dissipative conductivity in thin films of molybdenum nitride. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.94.064506.
Simmendinger, Julian, Pracht, Uwe S., Daschke, Lena, Proslier, Thomas, Klug, Jeffrey A., Dressel, Martin, & Scheffler, Marc. Superconducting energy scales and anomalous dissipative conductivity in thin films of molybdenum nitride. United States. doi:10.1103/PhysRevB.94.064506.
Simmendinger, Julian, Pracht, Uwe S., Daschke, Lena, Proslier, Thomas, Klug, Jeffrey A., Dressel, Martin, and Scheffler, Marc. Mon . "Superconducting energy scales and anomalous dissipative conductivity in thin films of molybdenum nitride". United States. doi:10.1103/PhysRevB.94.064506.
@article{osti_1375921,
title = {Superconducting energy scales and anomalous dissipative conductivity in thin films of molybdenum nitride},
author = {Simmendinger, Julian and Pracht, Uwe S. and Daschke, Lena and Proslier, Thomas and Klug, Jeffrey A. and Dressel, Martin and Scheffler, Marc},
abstractNote = {We report investigations of molybdenum nitride (MoN) thin films with different thickness and disorder and with superconducting transition temperature 9.89K >= T-c >= 2.78 K. Using terahertz frequency-domain spectroscopy we explore the normal and superconducting charge carrier dynamics for frequencies covering the range from 3 to 38 cm(-1) (0.1 to 1.1 THz). The superconducting energy scales, i.e., the critical temperature T-c, the pairing energy Delta, and the superfluid stiffness J, and the superfluid density n(s) can be well described within the Bardeen-Cooper-Schrieffer theory for conventional superconductors. At the same time, we find an anomalously large dissipative conductivity, which cannot be explained by thermally excited quasiparticles, but rather by a temperature-dependent normal-conducting fraction, persisting deep into the superconducting state. Our results on this disordered system constrain the regime, where discernible effects stemming from the disorder-induced superconductor-insulator transition possibly become relevant, to MoN films with a transition temperature lower than at least 2.78 K.},
doi = {10.1103/PhysRevB.94.064506},
journal = {Physical Review B},
number = 6,
volume = 94,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 2016},
month = {Mon Aug 01 00:00:00 EDT 2016}
}