Multi-band conductivity and multi-gap superconductivity in V3Si from optical measurements on films at terahertz frequencies

TL;DR

This study investigates multi-band conductivity and multi-gap superconductivity in V3Si thin films using terahertz optical measurements, revealing two contributing electronic bands and two superconducting gaps consistent with theoretical calculations.

Contribution

It provides experimental evidence for multi-band and multi-gap superconductivity in V3Si films through terahertz optical spectroscopy and detailed data analysis.

Findings

Evidence of two electronic bands contributing to conductivity.

Identification of two superconducting gaps with 2Δ/kTc values near 1.8 and 3.8.

Consistency with density functional theory calculations.

Abstract

The possibility of multi-band conductivity and multi-gap superconductivity is explored in oriented V3Si thin films by means of reflectance and transmittance measurements at terahertz frequencies. The temperature dependence of the transmittance spectra in the normal state gives evidence of two bands contributing to the film conductivity. This outcome is consistent with electronic structure calculations performed within density functional theory. On this basis, we performed a detailed data analysis and found that all optical data can be consistently accounted for within a two-band framework, with the presence of two optical gaps in the superconducting state corresponding to 2D=kTc values close to 1.8 and 3.8.