Microscopic investigation of superconducting properties of a strongly coupledsuperconductor IrGe via {\mu}SR

TL;DR

This study investigates the superconducting properties of IrGe, a strongly coupled superconductor, using various experimental techniques, revealing an isotropic s-wave pairing with strong electron-phonon coupling and preserved time-reversal symmetry.

Contribution

First detailed muon spin rotation/relaxation study of IrGe showing strong coupling and conventional s-wave superconductivity with preserved time-reversal symmetry.

Findings

IrGe exhibits strong electron-phonon coupling.

Superconductivity in IrGe is consistent with an isotropic s-wave gap.

Time-reversal symmetry is maintained in the superconducting state.

Abstract

Exploring superconductors which can possess pairing mechanism other than the BCS predicted s-wave have continually attracted considerable interest. Superconductors with low-lying phonons may exhibit unconventional superconductivity as the coupling of electrons with these low-lying phonons can potentially affect the nature of the superconducting ground state, resulting in strongly coupled superconductivity. In this work, by using magnetization, AC transport, specific heat, and muon spin rotation/relaxation ($\mu$SR) measurements, we report a detailed investigation on the superconducting ground state of the strongly coupled superconductor, IrGe, that has a transition temperature, T$_{C}$, at 4.7 K. Specific heat (SH), and transverse field $\mu$SR is best described with an isotropic s-wave model with strong electron-phonon coupling, indicated by the values of both $\Delta(0)/k_{B}T_{C}$ = 2.3, 2.1 (SH, $\mu$SR), and $\Delta C_{el}/\gamma_{n}T_{C}$ = 2.7. Zero-field $\mu$SR measurements confirm the presence of time-reversal symmetry in the superconducting state of IrGe.