Intrinsic and Extrinsic Spin-Orbit Coupling in Rhombohedral Graphene, Part I

ORAL

Abstract

Rhombohedral graphene multilayers host magnetism and both spin singlet and triplet superconductivity when doped through displacement field tuned van Hove singularities located near the band edge [1-4]. The role of the spin degree of freedom has been a key outstanding question in the many-body physics of these systems. In this first of two talks, we use high resolution capacitance and nanoSQUID on Tip (nSOT) magnetometry to investigate the phase diagram of generalized magnetic phases in rhombohedral graphene. I will focus on the “quarter metal” regime, where a valley imbalanced phase with a finite orbital magnetic moment competes with an intervalley coherent phase in which electron wave functions in the two momentum space valleys develop a macroscopically coherent relative phase. Unexpectedly, the delicate balance between these nearly degenerate phases reveals the influence of intrinsic spin-orbit coupling, which we measure to have a strength of approximately 50 micro-eV. In the intervalley coherent regime, spin orbit coupling nucleates new ground states with in- and out-of-plane spin anisotropy, with implications for the phase diagram of spin-triplet superconductivity observed in both bi- and trilayer graphene.



[1] Zhou, H., Xie, T., Ghazaryan, A., et al. Nature 598, 429–433 (2021).

[2] Zhou, H., Xie, T., Taniguchi, T. et al. Nature 598, 434–438 (2021).

[3] Zhou, H., Holleis, L., Saito, Y. et al. Science 375, 774-778 (2022).

[4] Zhang, Y., Polski, R., Thomson, A. et al. Nature 613, 268–273 (2023).

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Publication: Intervalley coherence and intrinsic spin-orbit coupling in rhombohedral trilayer graphene. T. Arp and O. Sheekey et al. arXiv:2310.03781

Presenters

  • Trevor B Arp

    • University of California, Santa Barbara

Authors

  • Trevor B Arp

    • University of California, Santa Barbara

  • Owen I Sheekey

    • University of California, Santa Barbara
    • University of California Santa Barbara
    • University of Santa Barbara
    • UCSB

  • Haoxin Zhou

    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • Charles L Tschirhart

    • Cornell University

  • Caitlin L Patterson

    • University of California, Santa Barbara

  • Heun Mo Yoo

    • University of California, Santa Barbara

  • Ludwig F Holleis

    • University of California, Santa Barbara

  • Evgeny Redekop

    • University of California, Santa Barbara

  • Grigory Babikyan

    • University of California, Santa Barbara

  • Tian Xie

    • university of California, Santa Barbra

  • Jiewen Xiao

    • Weizmann Institute of Science
    • Weizmann institute of Science

  • Yaar Vituri

    • Weizmann Institute of Science

  • Tobias Holder

    • Weizmann Institute of Science

  • Takashi Taniguchi

    • Kyoto Univ
    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Sciences
    • NIMS
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, NIMS, Japan
    • International Center for Materials Nanoarchitectonics, Tsukuba
    • National Institue for Materials Science
    • Kyoto University
    • National Institute of Materials Science
    • International Center for Materials Nanoarchitectonics and National Institute for Materials Science

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science

  • Martin E Huber

    • University of Colorado, Denver

  • Erez Berg

    • Weizmann Institute of Science
    • Weizmann

  • Andrea F Young

    • University of California, Santa Barbara