Nodeless Superconductivity in the Noncentrosymmetric Superconductor $Mg_{10}Ir_{19}B_{16}$

TL;DR

This study investigates the superconducting properties of the noncentrosymmetric compound Mg10Ir19B16, revealing nodeless s-wave superconductivity with weak coupling characteristics and specific electron-phonon interactions.

Contribution

It provides the first detailed measurements of the superconducting gap, coupling strength, and electron-phonon interactions in Mg10Ir19B16, a newly discovered noncentrosymmetric superconductor.

Findings

Superconducting gap has s-wave symmetry with Δ0 ≈ 0.6 meV.

The ratio Δ0/kBTc ≈ 1.86 indicates weak coupling.

Conduction electrons of Ir atoms interact mainly with their own vibrations.

Abstract

We measured the resistivity, diamagnetization and low temperature specific heat of the newly discovered noncentrosymmetric superconductor $Mg_{10}Ir_{19}B_{16}$. It is found that the superconducting gap has an s-wave symmetry with a value of about $\Delta_0 \approx$ 0.6 meV, and the ratio $\Delta_0/k_BT_c\approx1.86$ indicates a weak coupling for the superconductivity. The correlations among the normal state Sommerfeld constant $\gamma_n$, the slope $-d\mu_0H_{c2}(T)/dT$ near Tc and the condensation energy Ec are all consistent with the weak coupling picture. The separated phonon contribution from the specific heat shows that the conduction electrons of the $Ir$ atoms interact most strongly with the vibrations of themselves, instead of with that of the light element boron.