Pairing Fluctuation AC Conductivity of Disordered Thin Films

Abstract

We study temperature $T$ and frequency $\omega$ dependence of the in-plane fluctuation conductivity of a disordered superconducting film above the critical temperature. Our calculation is based on the nonlinear sigma model within the Keldysh technique. The fluctuation contributions of different physical origin are found and analyzed in a wide frequency range. In the low-frequency range, $\omega \ll T$, we reproduce the known leading terms and find additional subleading ones in the Aslamazov-Larkin and the Maki-Thompson contributions to the ac conductivity. We also calculate the density of states ac correction. In the dc case these contributions logarithmically depend on the Ginzburg-Landau rate and are considerably smaller that the leading ones. However, in the ac case an external finite-frequency electromagnetic field strongly suppresses the known Alsamazov-Larkin and Maki-Thompson ac contributions, while the corresponding new terms and the density of states contribution are weakly suppressed and therefore become relevant at finite frequencies.

14 pages

References in corpus (7)

• Superconducting phase transitions in ultrathin TiN films
• Frequency dependent superfluid stiffness in the pseudogap regime in strongly disordered NbN thin films
• Direct observation of the superconducting gap in thin film of titanium nitride using terahertz spectroscopy
• Fluctuation conductivity of thin films and nanowires near a parallel-field-tuned superconducting quantum phase transition
• Keldysh Ginzburg-Landau action of fluctuating superconductors
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• Fluctuation conductivity in disordered superconducting films

Cited by in corpus (3)

• Superconducting fluctuations at arbitrary disorder strength
• Critical Viscosity of a Fluctuating Superconductor
• Weak localization correction to linear absorption in conventional superconductors