Injection of spin-polarized current into superconducting β-Bi₂Pd and Nb thin films

In recent years, much interest has been garnered in searching for spin-triplet superconductors due to their potential applications in superconducting spintronics. While spin-singlet Cooper pairs experience pair-breaking under magnetic fields, spin-triplets are less susceptible to this effect thus making them more favorable in spintronics. One candidate material for spin-triplet superconductivity is β-Bi₂Pd, a centrosymmetric superconductor which has been reported to exhibit half-integer flux quantization consistent with spin-triplet pairing^[1]. In this work, we investigate the spin properties of β-Bi₂Pd’s superconductivity by the injection of spin-polarized current into β-Bi₂Pd thin films deposited via co-sputtering. A combinatorial approach is implemented to fine-tune the composition of β-Bi₂Pd thin films. We compare the pair-breaking effects of polarized current injection to β-Bi₂Pd with those into identically-made Nb devices.

^[1] Li, Y. et al., Science 366, 238–241 (2019)