Possible evidence for two-gap superconductivity in TiSe_2Cu_x

TL;DR

This study investigates superconductivity in TiSe_2Cu_x, revealing evidence for two-gap behavior and how the superfluid density and gap size evolve with copper doping, using TF-muSR measurements.

Contribution

It provides experimental evidence for two-gap superconductivity in TiSe_2Cu_x and details how the superconducting properties change with doping levels.

Findings

Superfluid density increases with x

Superconducting gap approaches BCS value at higher x

Evidence suggests presence of two superconducting gaps at low x

Abstract

We report a comprehensive TF-muSR study of TiSe_2Cu_2. The magnetic penetration depth was found to saturate at low temperature as expected in an s-wave SC. As x is increased we find that the superfluid density increases and the size of the superconducting gap, calculated from the temperature dependence of the superfluid density, is approaching the BCS value. However, for low values of x, the gap is smaller than the weak-coupling BCS prediction suggesting that two superconducting gaps are present in the sample.