Superconductivity in noncentrosymmetric NbReSi investigated by muon spin rotation and relaxation

TL;DR

This study investigates the superconducting properties of noncentrosymmetric NbReSi using muon spin techniques, revealing preserved time-reversal symmetry and an s-wave pairing state, contributing to understanding unconventional superconductivity in such materials.

Contribution

It provides detailed experimental insights into the superconducting state of NbReSi, highlighting the preservation of time-reversal symmetry and s-wave pairing, and suggests further research on similar materials.

Findings

No spontaneous magnetic field below T_c, indicating preserved time-reversal symmetry.

Confirms s-wave superconducting gap with Δ(0)/k_B T_c = 1.726.

Encourages further studies on noncentrosymmetric superconductors to explore unconventional behaviors.

Abstract

Noncentrosymmetric materials are promising paradigm to explore unconventional superconductivity. In particular, several Re containing noncentrosymmetric materials have attracted considerable attention due to a superconducting state with a broken time reversal symmetry. A comprehensive study on the superconducting ground state of NbReSi was investigated using magnetization, resistivity, and muon spin rotation/relaxation measurements. Zero field muon spectroscopy results showed the absence of any spontaneous magnetic field below the superconducting transition temperature, T$ _{c} $ = 6.29 K, indicating the preserved time-reversal symmetry. Transverse field muon spin rotation measurements confirms a s-wave nature of the sample with $\Delta(0)/k_{B}T_{c} $ = 1.726. This study urges further investigation on more noncentrosymmetric materials to elucidate the selective appearance of unconventional nature and unveil its dependence on antisymmetric spin-orbit coupling strength.