{
  "id": "2104.07335",
  "version": "v1",
  "published": "2021-04-15T09:50:09.000Z",
  "updated": "2021-04-15T09:50:09.000Z",
  "title": "Higher-Order Weyl-Exceptional-Ring Semimetals",
  "authors": [
    "Tao Liu",
    "James Jun He",
    "Zhongmin Yang",
    "Franco Nori"
  ],
  "comment": "14 pages, 8 figures. Comments and suggestions are welcome",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.quant-gas",
    "quant-ph"
  ],
  "abstract": "For first-order topological semimetals, non-Hermitian perturbation can drive the Weyl nodes into Weyl exceptional rings having multiple topological structures and no Hermitian counterparts. Recently, it was discovered that higher-order Weyl semimetals, as a novel class of higher-order topological phases, can uniquely exhibit coexisting surface and hinge Fermi arcs. However, non-Hermitian higher-order topological semimetals have not yet been explored. Here, we identify a new type of topological semimetals, i.e, a higher-order topological semimetal with Weyl exceptional rings. In such a semimetal, these rings are characterized by both a spectral winding number and a Chern number. Moreover, the higher-order Weyl-exceptional-ring semimetal supports both surface and hinge Fermi-arc states, which are bounded by the projection of the Weyl exceptional rings onto the surface and hinge, respectively. Our studies open new avenues for exploring novel higher-order topological semimetals in non-Hermitian systems.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-04-15T09:50:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "higher-order weyl-exceptional-ring semimetal",
      "weyl exceptional rings",
      "non-hermitian",
      "hinge fermi arcs",
      "exploring novel higher-order topological semimetals"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}