{
  "id": "1910.14606",
  "version": "v1",
  "published": "2019-10-31T16:57:09.000Z",
  "updated": "2019-10-31T16:57:09.000Z",
  "title": "Non-Hermitian topological phase transitions for quantum spin Hall insulators",
  "authors": [
    "Junpeng Hou",
    "Ya-Jie Wu",
    "Chuanwei Zhang"
  ],
  "comment": "10 pages, 9 figures",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.quant-gas",
    "physics.optics"
  ],
  "abstract": "The interplay between non-Hermiticity and topology opens an exciting avenue for engineering novel topological matter with unprecedented properties. While previous studies have mainly focused on one-dimensional systems or Chern insulators, here we investigate topological phase transitions to/from quantum spin Hall (QSH) insulators driven by non-Hermiticity. We show that a trivial to QSH insulator phase transition can be induced by solely varying non-Hermitian terms, and there exists exceptional edge arcs in QSH phases. We establish two topological invariants for characterizing the non-Hermitian phase transitions: i) with time-reversal symmetry, the biorthogonal $\\mathbb{Z}_2$ invariant based on non-Hermitian Wilson loops, and ii) without time-reversal symmetry, a biorthogonal spin Chern number through biorthogonal decompositions of the Bloch bundle of the occupied bands. These topological invariants can be applied to a wide class of non-Hermitian topological phases beyond Chern classes, and provides a powerful tool for exploring novel non-Hermitian topological matter and their device applications.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-10-31T16:57:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum spin hall insulators",
      "non-hermitian topological phase transitions",
      "transitions to/from quantum spin",
      "phase transitions to/from quantum"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}