{
  "id": "0712.0825",
  "version": "v2",
  "published": "2007-12-05T22:56:02.000Z",
  "updated": "2008-03-30T07:56:29.000Z",
  "title": "Interaction effects in 2D electron gas in a random magnetic field: Implications for composite fermions and quantum critical point",
  "authors": [
    "T. A. Sedrakyan",
    "M. E. Raikh"
  ],
  "comment": "32 pages, 15 figures, Revtex",
  "journal": "Phys. Rev. B 77, 115353 (2008)",
  "doi": "10.1103/PhysRevB.77.115353",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We consider a clean two-dimensional interacting electron gas subject to a random perpendicular magnetic field, h({\\bf r}). The field is nonquantizing, in the sense, that {\\cal N}_h-a typical flux into the area \\lambda_{\\text{\\tiny F}}^2 in the units of the flux quantum (\\lambda_{\\text{\\tiny F}} is the de Broglie wavelength) is small, {\\cal N}_h\\ll 1. If the spacial scale, \\xi, of change of h({\\bf r}) is much larger than \\lambda_{\\text{\\tiny F}}, the electrons move along semiclassical trajectories. We demonstrate that a weak field-induced curving of the trajectories affects the interaction-induced electron lifetime in a singular fashion: it gives rise to the correction to the lifetime with a very sharp energy dependence. The correction persists within the interval \\omega \\sim \\omega_0= E_{\\text{\\tiny F}}{\\cal N}_h^{2/3} much smaller than the Fermi energy, E_{\\text{\\tiny F}}. It emerges in the third order in the interaction strength; the underlying physics is that a small phase volume \\sim (\\omega/E_{\\text{\\tiny F}})^{1/2} for scattering processes, involving {\\em two} electron-hole pairs, is suppressed by curving. Even more surprising effect that we find is that {\\em disorder-averaged} interaction correction to the density of states, \\delta\\nu(\\omega), exhibits {\\em oscillatory} behavior, periodic in \\bigl(\\omega/\\omega_0\\bigr)^{3/2}. In our calculations of interaction corrections random field is incorporated via the phases of the Green functions in the coordinate space. We discuss the relevance of the new low-energy scale for realizations of a smooth random field in composite fermions and in disordered phase of spin-fermion model of ferromagnetic quantum criticality.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2008-03-30T07:56:29.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "73.40.Gk",
      "71.10.Pm",
      "71.10.Ay",
      "71.70.Di"
    ],
    "keywords": [
      "random magnetic field",
      "2d electron gas",
      "quantum critical point",
      "composite fermions",
      "interaction effects"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review B",
      "year": 2008,
      "month": "Mar",
      "volume": 77,
      "number": 11,
      "pages": 115353
    },
    "note": {
      "typesetting": "RevTeX",
      "pages": 32,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2008PhRvB..77k5353S"
    }
  }
}