Electromagnetic properties of impure superconductors with pair-breaking processes

Abstract

Recently a generic model has been proposed for the single-particle properties of gapless superconductors with simultaneously present pair-conserving and pair-breaking impurity scattering (the so-called Dynes superconductors). Here we calculate the optical conductivity of the Dynes superconductors. Our approach is applicable for all disorder strengths from the clean up to the dirty limit and for all relative ratios of the two types of scattering, nevertheless the complexity of our description is equivalent to that of the widely used Mattis-Bardeen theory. We identify two optical fingerprints of the Dynes superconductors: (i) the presence of two absorption edges and (ii) a finite absorption at vanishing frequencies even at the lowest temperatures. We demonstrate that the recent anomalous optical data on thin MoN films can be reasonably fitted by our theory.

9 pages, 8 figures, references added, explanation added, typos removed, results unchanged, sent to PRB

References in corpus (4)

• Point nodes persisting far beyond Tc in Bi2212
• On the Relation between Optical Conductivity and Quasiparticle Dynamics: Boson Structures
• Superconducting Energy Scales and Anomalous Dissipative Conductivity in Thin Films of Molybdenum Nitride
• Consistent two-lifetime model for spectral functions of superconductors

Cited by in corpus (5)

• Surface impedance and optimum surface resistance of a superconductor with imperfect surface
• Thermodynamic properties of the Dynes superconductors
• Design and Performance of Hafnium Optical and Near-IR Kinetic Inductance Detectors
• Tuning microwave losses in superconducting resonators
• Quantum dynamics of hydrogen in iron-based superconductor LaFeAsO0.9D0.1 measured with inelastic neutron spectroscopy