Observation of quantum corrections to conductivity up to optical frequencies

Abstract

It is well known that conductivity of disordered metals is suppressed in the limit of low frequencies and temperatures by quantum corrections. Although predicted by theory to exist up to much higher energies, such corrections have so far been experimentally proven only for $\lesssim$80 meV. Here, by a combination of transport and optical studies, we demonstrate that the quantum corrections are present in strongly disordered conductor MoC up to at least $\sim$4 eV, thereby extending the experimental window where such corrections were found by a factor of 50. The knowledge of both, the real and imaginary parts of conductivity, enables us to identify the microscopic parameters of the conduction electron fluid. We find that the conduction electron density of strongly disordered MoC is surprisingly high and we argue that this should be considered a generic property of metals on the verge of disorder-induced localization transition.

arXiv comment8 pages, 6 figures

References in corpus (4)

• Temperature dependence of resistivity and Hall-coefficient in a strongly disordered metal: NbN
• Fermionic scenario for the destruction of superconductivity in ultrathin MoC films evidenced by STM measurements
• Chebyshev expansion approach to the AC conductivity of the Anderson model
• Superconducting fluctuations in a thin NbN film probed by the Hall effect

Cited by in corpus (7)

• Zeeman driven superconductor insulator transition in strongly disordered MoC film. STM and transport studies in transverse magnetic field
• Optical and transport properties of NbN thin films revisited
• A numerical extrapolation method for complex conductivity of disordered metals
• Model-independent determination of the gap function of nearly localized superconductors
• Numerical modeling of SNSPD absorption utilizing optical conductivity with quantum corrections
• Onset of superconductor-insulator transition in an ultrathin NbN film under in-plane magnetic field studied by terahertz spectroscopy
• Photothermal resistivity alignment of optical fibers to SNSPD