Spin-triplet Superconductivity Evidenced by Half Quantum Flux in a Non-centrosymmetric Superconductor

ORAL

Abstract

Spin-triplet superconductors, rare and challenging to identify, play central roles in Majorana fermions and quantum computing. It has been proposed that superconductors with broken inversion symmetry may host spin-triplet Cooper pairs. Unique features of half-quantum fluxoid in flux quantization is one of the few methods that can identify spin-triplet superconductors [1]. We fabricated thin films of non-centrosymmetric α-BiPd by sputtering and patterned them into sub-µm-sized rings. Measurements of the Little-Parks oscillations in magnetoresistance show half-quantum fluxoid (n + ½)Φo, a key signature of spin-triplet pairing, where flux quantum Φo = hc/2e and n is an integer. Our extensive measurements support an admixture of pairing states of spin-singlet and spin-triplet Cooper pairs in α-BiPd [2].

[1] Li, Xu, Lee, Chu, and Chien, Science 366, 238 (2019)
[2] Xu, Li, Chien, Phys. Rev. Lett. 124, 167001 (2020)

*We acknowledge the support from the U.S. Department of Energy (DOE), Basic Energy Science Award No. DE-SC0009390. X. X. was supported in part by Spins and Heat in Nanoscale Electronic Systems (SHINES), an Energy Frontier Research Center (EFRC) funded by U.S. DOE Basic Energy Science Award No. DESC0012670.

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Presenters

  • Xiaoying Xu

    • Johns Hopkins University

Authors

  • Xiaoying Xu

    • Johns Hopkins University

  • Yufan Li

    • Johns Hopkins University

  • C. L. Chien

    • Physics and Astronomy, Johns Hopkins University
    • Johns Hopkins University