Studies of the superconducting properties of Sn1-xInxTe (x=0.38 to 0.45) using muon-spin spectroscopy

TL;DR

This study investigates the superconducting properties of Sn1-xInxTe with varying indium content using muon-spin spectroscopy, revealing increased Tc, preserved time-reversal symmetry, and a single-gap s-wave superconducting state.

Contribution

It provides detailed muSR measurements showing the evolution of superconducting parameters and confirms the single-gap s-wave nature across compositions.

Findings

Tc increases with indium content, reaching 4.8 K at x=0.45

Time-reversal symmetry remains preserved in all samples

Superconductivity is characterized by a single-gap s-wave model

Abstract

The superconducting properties of Sn1-xInxTe (x = 0.38 to 0.45) have been studied using magnetization and muon-spin rotation or relaxation (muSR) measurements. These measurements show that the superconducting critical temperature Tc of Sn1-xInxTe increases with increasing x, reaching a maximum at around 4.8 K for x = 0.45. Zero-field muSR results indicate that time-reversal symmetry is preserved in this material. Transverse-field muon-spin rotation has been used to study the temperature dependence of the magnetic penetration depth lambda(T) in the mixed state. For all the compositions studied, lambda(T) can be well described using a single-gap s-wave BCS model. The magnetic penetration depth at zero temperature lambda(0) ranges from 500 to 580 nm. Both the superconducting gap Delta(0) at 0 K and the gap ratio Delta(0)/kBTc indicate that Sn1-xInxTe (x = 0.38 to 0.45) should be considered as a superconductor with intermediate to strong coupling.