{
  "id": "1808.09212",
  "version": "v1",
  "published": "2018-08-28T10:38:04.000Z",
  "updated": "2018-08-28T10:38:04.000Z",
  "title": "Spontaneous symmetry breaking in coupled Bose-Einstein condensates",
  "authors": [
    "Hal Tasaki"
  ],
  "comment": "12 pages, no figures",
  "categories": [
    "cond-mat.stat-mech",
    "cond-mat.quant-gas",
    "math-ph",
    "math.MP",
    "quant-ph"
  ],
  "abstract": "We study a system of two hardcore bosonic Hubbard models weakly coupled with each other by tunneling. Assuming that the single uncoupled model exhibits off-diagonal long-range order, we prove that the system exhibits spontaneous symmetry breaking (SSB) in the infinite volume limit, in the sense that the two subsystems maintain a definite relative U(1) phase when the tunneling is turned off. Although SSB of the U(1) phase is never observable in a single system, SSB of the relative U(1) phase is physically meaningful and observable by interference experiments. The present theorem is made possible by the rigorous theory of low-lying states and SSB in quantum antiferromagnets developed over the years.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-08-28T10:38:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spontaneous symmetry breaking",
      "coupled bose-einstein condensates",
      "hardcore bosonic hubbard models",
      "off-diagonal long-range order",
      "infinite volume limit"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}