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Observation of half-quantum flux in topological superconductor β-Bi<sub>2</sub>Pd

ORAL

Abstract

Magnetic flux quantization is one of the defining characteristics of a superconductor. We report the observation of half-integer magnetic flux quantization in mesoscopic rings of superconducting β-Bi2Pd thin films [1]. The half-quantum fluxoid manifests itself as a π-phase shift in the quantum oscillations of the superconducting critical temperature. The superconducting ring energetically prefers half flux quanta with fractional quantum numbers of 1/2, 3/2, 5/2, etc., instead of usual integer numbers of 0, 1, 2, etc. This result is consistent with β-Bi2Pd having a spin-triplet pairing symmetry, which may be expected from β-Bi2Pd as a topological supercondcutor [2,3]. Our findings usher in new venues for studying topological superconductivity, and new designs of flux qubit for quantum computing, which may operate without external magnetic fields.

[1] Y. Li et al., Science 366, 238-241 (2019).
[2] M. Sakano, et al., Nature Communications 6, 8595 (2015).
[3] K. Iwaya, et al., Nature Communications 8, 976 (2017).

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Presenters

  • Yufan Li

    Johns Hopkins University, Department of Physics and Astronomy, Johns Hopkins University

Authors

  • Yufan Li

    Johns Hopkins University, Department of Physics and Astronomy, Johns Hopkins University

  • Xiaoying Xu

    Johns Hopkins University

  • M.-H. Lee

    Center for Condensed Matter Sciences and Center of Atomic Initiative for New Materials, National Taiwan University

  • M.-W Chu

    Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan, China, Center for Condensed Matter Sciences and Center of Atomic Initiative for New Materials, National Taiwan University, Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan

  • Chia-Ling Chien

    Department of Physics and Astronomy, Johns Hopkins University, Johns Hopkins University