{
  "id": "1512.04350",
  "version": "v1",
  "published": "2015-12-14T14:58:15.000Z",
  "updated": "2015-12-14T14:58:15.000Z",
  "title": "Identifying the closeness of eigenstates in quantum many-body systems",
  "authors": [
    "Haibin Li",
    "Yang Yang",
    "Pei Wang",
    "Xiaoguang Wang"
  ],
  "comment": "7 pages, 4 figures",
  "categories": [
    "cond-mat.stat-mech",
    "quant-ph"
  ],
  "abstract": "We propose a new quantity called modulus fidelity to measure the closeness of two quantum pure states. Especially, we use it to investigate the closeness of eigenstates of quantum many-body systems. When the system is integrable, the modulus fidelity of neighbor eigenstates displays a large fluctuation. But the modulus fidelity is close to a constant when system becomes non-integrable with fluctuation reduced drastically. Average modulus fidelity of neighbor eigenstates increases with the increase of parameters that destroy the integrability, which also indicates the integrable-chaos transition. In non-integrable case, it is found two eigenstates are closer to each other if their level spacing is small. We also show that the closeness of eigenstates in non-integrable domain is the underlying mechanism of \\emph{eigenstate thermalization hypothesis} (ETH) which explains the thermalization in nonintegrable system we studied.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-12-14T14:58:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum many-body systems",
      "neighbor eigenstates increases",
      "neighbor eigenstates displays",
      "quantum pure states",
      "average modulus fidelity"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}