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Non-Hermitian topology and skin effect in Co-graphene nanoribbons

ORAL

Abstract

Recently, non-Hermitian effects on the topology of quantum materials have attracted much interest due to their unusual properties compared to Hermitian topology. A distinct character of non-Hermitian topology is that it breaks the limitation of the requirement of a real band gap. The system may not have a gap in the real spectrum but could still be topological as long as a point gap in the complex spectrum exists. However, the way of realizing non-Hermitian topology in a realistic 1D condensed matter system is still missing. In this work, we study a particular type of graphene nanoribbon with cobalt adatoms (Co-GNR). Due to many-electron interactions, the Hamiltonian characterizing quasiparticle excitations becomes non-Hermitian. The strong spin-orbit coupling brought by the cobalt atoms induces non-trivial non-Hermitian topology in the GW quasiparticle band structure. We extract effective tight-binding parameters with a Wannier function basis and unveil the non-Hermitian skin effect in Co-GNR.

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Presenters

  • Jingwei Jiang

    University of California, Berkeley

Authors

  • Jingwei Jiang

    University of California, Berkeley

  • Zhenglu Li

    Department of Physics, University of California, Berkeley, UC Berkeley & Lawrence Berkeley National Laboratory, University of California at Berkeley, and Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, University of California, Berkeley, Lawrence Berkeley National Laboratory and University of California at Berkeley, Department of physics, University of California at Berkeley, Berkeley, California

  • Jiawei Ruan

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

  • Steven G Louie

    University of California, Berkeley, Department of Physics, University of California, Berkeley, University of California at Berkeley and Lawrence Berkeley National Laboratory, UC Berkeley & Lawrence Berkeley National Laboratory, University of California at Berkeley, and Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Department of physics, University of California at Berkeley, Berkeley, California