Nematicity from incipient electron flat bands in a kagomé metal

ORAL

Abstract

Here, we present evidence for nematicity arising from incipient flat electronic bands away from the Fermi level in a kagomé metal CoSn. We use a combination of techniques probing thermodynamic (specific heat, magnetostriction), structural (neutron scattering) and electronic (resonant x-ray scattering) properties of the system to probe even minute distortions. The rotational symmetry breaking exists in a finite temperature range centered near T* = 225 K and is accompanied by strong magnetocaloric anomalies. We attribute the observed phenomena to the pronounced enhancement of system's susceptibility to rotational symmetry-breaking driven by the thermally-activated electron flat band carriers. Our findings point towards the possibilities realization new phases of matter with non-degenerate, thermally activated flat-band electrons.

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Presenters

  • Nathan C Drucker

    • Harvard University

Authors

  • Nathan C Drucker

    • Harvard University

  • Thanh Nguyen

    • Massachusetts Institute of Technology

  • MANASI MANDAL

    • Massachusetts Institute of Technology

  • Phum Siriviboon

    • Brown University

  • Yujie Quan

    • University of California, Santa Barbara

  • Douglas L Abernathy

    • Oak Ridge National Lab

  • Songxue Chi

    • Oak Ridge National Laboratory

  • Fankang Li

    • Oak Ridge National Laboratory

  • Christie Nelson

    • Brookhaven National Laboratory

  • Travis J Williams

    • Oak Ridge National Laboratory

  • Masaaki Matsuda

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Bolin Liao

    • University of California, Santa Barbara

  • Pavel A Volkov

    • University of Connecticut

  • Mingda Li

    • Massachusetts Institute of Technology MI

  • Mingda Li

    • Massachusetts Institute of Technology MI