High Temperature Fermi Statistics from Majorana Fermions in an Insulating Magnet

ORAL

Abstract

Majorana fermions, particles that are their own anti-particles, can emerge in insulating magnets as excitations with fractions of the constituent's quantum numbers. Interest in Majoranas is driven by their potential for quantum computation, and as evidence of novel topological states. Observations have been limited to liquid helium temperatures as edge modes in topological superconductors and quantum spin liquids (QSL) without combined evidence of particle-hole symmetry, Fermi statistics, and presence in the bulk. Here we report all three in α-RuCl3, at temperatures exceeding liquid nitrogen via new energy gain as well as loss Raman spectra and a unique framework to identify the statistical properties of the Kitaev QSL. α-RuCl3 is close to the Kitaev QSL, where bond-dependent Ising interactions produce excitations that are non-local in terms of spin flips. Consistent with particle-hole symmetric excitations obeying Paul-exclusion, the sum of the energy loss and gain responses are nearly temperature and energy independent. Our new method can be used to identify the unique properties of QSLs, and demonstrates the promise of α-RuCl3 for efforts in topological phases and quantum computation.

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Presenters

  • Yiping Wang

    Boston College

Authors

  • Yiping Wang

    Boston College

  • Gavin B Osterhoudt

    Boston College

  • Yao Tian

    Apple inc.

  • Paula J Kelley

    University of Tennessee (Knoxville, USA), Oak Ridge National Lab, Oak Ridge National Laboratory

  • Arnab Banerjee

    Oak Ridge National Laboratory, Oak Ridge National Lab

  • Thomas A Goldstein

    Department of Physics, University of Massachusetts Amherst, Physics, University of Massachusetts - Amherst, umass Amherst

  • Jun Yan

    Department of Physics, University of Massachusetts Amherst, Physics, University of Massachusetts - Amherst, umass Amherst

  • Johannes Knolle

    Blackett Laboratory, Imperial College London

  • Joji Nasu

    Tokyo Institute of Technology, Physics, Tokyo Institute of Technology, Department of Physics, Tokyo Institute of Technology

  • Yukitoshi Motome

    Department of Applied Physics, University of Tokyo, Department of Applied Physics, The University of Tokyo, The University of Tokyo, University of Tokyo, Applied Physics, University of Tokyo

  • Stephen Nagler

    Oak Ridge National Laboratory (USA), Oak Ridge National Laboratory, Oak Ridge National Lab, Neutron Scattering Division, Oak Ridge National Laboratory

  • David George Mandrus

    Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA, University of Tennessee-Knoxville, Oak Ridge National Lab, Department of Materials Science and Engineering, University of Tennessee, University of Tennessee (Knoxville, USA), Department of Materials Science and Engineering, University of Tennessee Knoxville, Department of Material Science & Engineering, University of Tennessee, Material Science and Engineering, University of Tennessee, Materials Science and Technology, Materials Science and Technology, University of Tennessee, Knoxville, Department of Materials Science and Engineering, The University of Tennessee, Materials Science and Engineering, The University of Tennessee, Oak Ridge National Laboratory, Department of Material Science and Engineering, University of Tennessee

  • Kenneth Burch

    Boston College