Rhenium based noncentrosymmetric superconductors crystallizing in α-Mn structure have become potential candidates to exhibit an unconventional superconducting ground-state. Here we report a detailed investigation on the superconducting and normal state properties of Re5.5Ta, that also has the α-Mn structure. Magnetization, specific heat, and transport measurements confirm the bulk superconducting transition \textit{T}C at 8.0 K. Upper critical field value (HC2(0)) calculated from magnetization, specific heat and AC transport measurements exceed the Pauli paramagnetic limit (14.7 T), indicating that the superconducting properties of Re5.5Ta are probably unconventional in nature. However, low-temperature specific heat and transverse-field muon spin rotation measurements suggest a surprising nodeless isotropic superconducting gap, although with strong electron-phonon coupling.
@article{arxiv.2004.03834,
title = {Unconventional superconducting properties of noncentrosymmetric Re5.5Ta},
author = {Arushi and D. Singh and P. K. Biswas and A. D. Hillier and R. P. Singh},
journal= {arXiv preprint arXiv:2004.03834},
year = {2020}
}