Upper critical magnetic field in NbRe and NbReN micrometric strips

Abstract

Non-centrosymmetric superconductors have recently received significant interest due to their intriguing physical properties such as multigap and nodal superconductivity, helical vortex states, as well as non-trivial topological effects. Moreover, large values of the upper critical magnetic field have been reported in these materials. Here, we focus on the study of the temperature dependence of the perpendicular magnetic field of NbRe and NbReN films patterned in micrometric strips. The experimental data are studied within the Werthamer–Helfand–Hohenberg theory, which considers both orbital and Zeeman pair breaking. The analysis of the results shows different behavior for the two materials with a Pauli contribution relevant only in the case of NbReN.

Investigation of NbRe for superconducting microstrips single photon detectors

“…A promising material that has been proposed for the fabrication of SNSPDs is NbRe [21]. Ultrathin NbRe films are homogenous and polycrystalline with a nano-crystallite diameter of about 3 nm [22,23]. The energy gap is intermediate between the polycrystalline and amorphous materials, and the quasiparticle relaxation time is very short [24].…”