Low-energy electrodynamics of superconducting diamond

TL;DR

This study investigates the electrodynamics of boron-doped superconducting diamond films, revealing their behavior as dirty BCS superconductors through optical measurements and analysis of key superconducting parameters.

Contribution

First measurement of the low-energy electrodynamics of superconducting diamond films using advanced reflectivity techniques.

Findings

Determined the optical gap and penetration depth of the superconducting diamond.

Confirmed the dirty BCS superconductor behavior of boron-doped diamond.

Analyzed the electron-phonon spectral function and sum rule range.

Abstract

Heavily-boron-doped diamond films become superconducting with critical temperatures $T_c$ well above 4 K. Here we first measure the reflectivity of such a film down to 5 cm$^{-1}$, by also using Coherent Synchrotron Radiation. We thus determine the optical gap, the field penetration depth, the range of action of the Ferrell-Glover-Tinkham sum rule, and the electron-phonon spectral function. We conclude that diamond behaves as a dirty BCS superconductor.