{
  "id": "cond-mat/0412220",
  "version": "v2",
  "published": "2004-12-09T08:57:19.000Z",
  "updated": "2004-12-27T03:52:52.000Z",
  "title": "Fermi liquid theory for the nonequilibrium Kondo effect at low bias voltages",
  "authors": [
    "Akira Oguri"
  ],
  "comment": "8 pages, to appear in a special edition of JPSJ \"Kondo Effect -- 40 Years after the Discovery\", typos are corrected",
  "journal": "J. Phys. Soc. Jpn. 74, 110 (2005)",
  "doi": "10.1143/JPSJ.74.110",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.str-el"
  ],
  "abstract": "In this report, we describe a recent development in a Fermi liquid theory for the Kondo effect in quantum dots under a finite bias voltage $V$. Applying the microscopic theory of Yamada and Yosida to a nonequilibrium steady state, we derive the Ward identities for the Keldysh Green's function, and determine the low-energy behavior of the differential conductance $dI/dV$ exactly up to terms of order $(eV)^2$ for the symmetric Anderson model. These results are deduced from the fact that the Green's function at the impurity site is a functional of a nonequilibrium distribution $f_{\\text{eff}}(\\omega)$, which at $eV=0$ coincides with the Fermi function. Furthermore, we provide an alternative description of the low-energy properties using a renormalized perturbation theory (RPT). In the nonequilibrium state the unperturbed part of the RPT is determined by the renormalized free quasiparticles, the distribution function of which is given by $f_{\\text{eff}}(\\omega)$. The residual interaction between the quasiparticles $\\widetilde{U}$, which is defined by the full vertex part at zero frequencies, is taken into account by an expansion in the power series of $\\widetilde{U}$. We also discuss the application of the RPT to a high-bias region beyond the Fermi-liquid regime.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2004-12-27T03:52:52.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fermi liquid theory",
      "low bias voltages",
      "nonequilibrium kondo effect",
      "nonequilibrium steady state",
      "keldysh greens function"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}