Testing V3Si for two-band superconductivity

Abstract

Is V3Si a two-band or a single-band superconductor? Everyone who searches the literature for this question will find conflicting answers, for V3Si was claimed to be a perfect example of two-band and claimed to be a perfect example of single-band superconductivity. In this article we intend to clarify the situation by presenting new experimental facts acquired from the magnetic properties of a V3Si single crystal. We probe for field dependent two-band effects by analyzing the reversible magnetization at different temperatures, and we probe for temperature dependent two-band effects by analyzing the superfluid density obtained by two different methods at different magnetic fields. All our results are reliably described within the single-band models and thus support the single-band scenario for V3Si but do not completely rule out the presence of a very small second gap.