Abstract

The bismuth-based half-Heusler materials host a nontrivial topological band structure, unconventional superconductivity, and large spin-orbit coupling in a system with very low electron density. In particular, the inversion of p-orbital-derived bands with an effective angular momentum j of up to 3/2 is thought to play a central role in anomalous Cooper pairing in the cubic half-Heusler semimetal YPtBi, which is thought to be the first "high-spin" superconductor. Here, we report an extensive study of the angular dependence of quantum oscillations (QOs) in the electrical conductivity of YPtBi, revealing an anomalous Shubnikov-de Haas effect consistent with the presence of a coherent j=3/2 Fermi surface. The QO signal in YPtBi manifests an extreme anisotropy upon rotation of the magnetic field from the [100] to [110] crystallographic direction, where the QO amplitude vanishes. This radical anisotropy for such a highly isotropic system cannot be explained by trivial scenarios involving changes in effective mass or impurity scattering, but rather is naturally explained by the warping feature of the j=3/2 Fermi surface of YPtBi, providing direct proof of active high angular momentum quasiparticles in the half-Heusler compounds.

Department(s)

Physics

Comments

National Science Foundation, Grant PHY-1607611

International Standard Serial Number (ISSN)

2643-1564

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2023 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Jul 2022

Included in

Physics Commons

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