{
  "id": "0906.0891",
  "version": "v3",
  "published": "2009-06-04T14:10:10.000Z",
  "updated": "2009-09-15T12:34:49.000Z",
  "title": "Semiclassical transport in nearly symmetric quantum dots I: symmetry-breaking in the dot",
  "authors": [
    "Robert S. Whitney",
    "Henning Schomerus",
    "Marten Kopp"
  ],
  "comment": "(18pages - 9figs) This is the first of a pair of articles (v3 minor improvements to text)",
  "journal": "Phys. Rev. E 80, 056209 (2009)",
  "doi": "10.1103/PhysRevE.80.056209",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.dis-nn",
    "nlin.CD"
  ],
  "abstract": "We apply the semiclassical theory of transport to quantum dots with exact and approximate spatial symmetries; left-right mirror symmetry, up-down mirror symmetry, inversion symmetry or four-fold symmetry. In this work - the first of a pair of articles - we consider (a) perfectly symmetric dots and (b) nearly symmetric dots in which the symmetry is broken by the dot's internal dynamics. The second article addresses symmetry-breaking by displacement of the leads. Using semiclassics, we identify the origin of the symmetry-induced interference effects that contribute to weak-localization corrections and universal conductance fluctuations. For perfect spatial symmetry, we recover results previously found using the random-matrix theory conjecture. We then go on to show how the results are affected by asymmetries in the dot, magnetic fields and decoherence. In particular, the symmetry-asymmetry crossover is found to be described by a universal dependence on an asymmetry parameter $\\gamma_{asym}$. However, the form of this parameter is very different depending on how the dot is deformed away from spatial symmetry. Symmetry-induced interference effects are completely destroyed when the dot's boundary is globally deformed by less than an electron wavelength. In contrast, these effects are only reduced by a finite amount when a part of the dot's boundary smaller than a lead-width is deformed an arbitrarily large distance.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2009-09-15T12:34:49.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "05.45.Mt",
      "74.40.+k",
      "73.23.-b",
      "03.65.Yz"
    ],
    "keywords": [
      "symmetric quantum dots",
      "semiclassical transport",
      "symmetry-induced interference effects",
      "symmetric dots",
      "up-down mirror symmetry"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review E",
      "year": 2009,
      "month": "Nov",
      "volume": 80,
      "number": 5,
      "pages": "056209"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2009PhRvE..80e6209W"
    }
  }
}