Evidence fors-wave superconductivity in noncentrosymmetricRe3Wfrom magnetic penetration depth measurements

Abstract

We report measurements of the temperature dependence of the magnetic penetration depth $\ensuremath{\lambda}(T)$ in noncentrosymmetric superconductor ${\mathrm{Re}}_{3}\mathrm{W}$. We employed two experimental techniques: extraction of $\ensuremath{\lambda}(T)$ from magnetic dc susceptibility, measured on a powder sample, and the rf tunnel diode resonator technique, where a bulk polycrystalline sample was used. The results of both techniques agree: the temperature dependence of the penetration depth can be well described by weak-coupling, dirty-limit, $s$-wave BCS theory where we obtain $\ensuremath{\Delta}(0)∕{k}_{B}{T}_{C}=1.76\ifmmode\pm\else\textpm\fi{}0.05$. No evidence for unconventional pairing resulting from the absence of the inversion symmetry is found.