Observation of Chiral Phonons with Giant Magnetic Moments in a Topological Crystalline Insulator

ORAL

Abstract

Chiral phonons present peculiar properties in magnetic fields such as: magnetic circular dichroism, phonon Zeeman effect and phonon diamagnetic shift. Recent experimental studies reported magnetic moment values in a broad range up to several Bohr magnetons. On the other hand, theoretical reports predicted the dependence of the phonon magnetic moment on electronic contributions. Here, we present experiments in a set of thin films of the pseudobinary alloy Pb(1−x)Sn(x)Te which is known to show an x-dependent topological phase transition for x > 0.32 and has exhibited chiral phonons in strong magnetic fields for x = 0. At low temperatures and under magnetic fields up to 29.5 T, two optical phonons modes acquired circular polarization with opposite handedness. While the topologically trivial films (x

*This research was supported by NSF MRSEC No. DMR-1720595 and DMR-2114825, the Brasil@Rice Collaborative Grant, FAPESP Grants No. 2015/16191-5 and 2018/06142-5, CNPq Grants No. 307737/2020-9 and 307192/2021-0 and by the JSPS KAKENHI No. 20H05662.

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Publication: arXiv: 2208.12235 (25 Aug 2022)

Presenters

  • Felix G Hernandez

    • University of Sao Paulo

Authors

  • Felix G Hernandez

    • University of Sao Paulo

  • Andrey Baydin

    • Rice University

  • Swati Chaudhary

    • Northeastern University
    • University at Texas at Austin
    • Caltech
    • The University of Texas at Austin, Northeastern University, Massachusetts Institute of Technology
    • University of Texas at Austin
    • The university of Texas at Austin

  • Fuyang Tay

    • Rice University

  • Ikufumi Katayama

    • Yokohama National University

  • Jun Takeda

    • Yokohama National University

  • Hiroyuki Nojiri

    • Tohoku University

  • Anderson Okazaki

    • Brazilian Center for Research in Energy and Materials

  • Paulo Rappl

    • Instituto Nacional de Pesquisas Espaciais

  • Eduardo Abramof

    • Instituto Nacional de Pesquisas Espaciais

  • Martin A Rodriguez-vega

    • Theoretical Division, Los Alamos National Laboratory
    • University of Texas at Austin
    • University of Texas at Austin, Northeastern University

  • Gregory A Fiete

    • Northeastern University
    • Northeastern University, Massachusetts Institute of Technology

  • Junichiro Kono

    • Rice University