{
  "id": "cond-mat/0105110",
  "version": "v2",
  "published": "2001-05-04T19:53:04.000Z",
  "updated": "2001-09-19T16:05:20.000Z",
  "title": "Free Energy Functional for Nonequilibrium Systems: An Exactly Solvable Case",
  "authors": [
    "B. Derrida",
    "J. L. Lebowitz",
    "E. R. Speer"
  ],
  "comment": "4 pages, RevTeX. Changes: correct minor errors, add reference, minor rewriting requested by editors and referee",
  "journal": "Phys. Rev. Lett. 87, Issue 15, 150601 (2001)",
  "doi": "10.1103/PhysRevLett.87.150601",
  "categories": [
    "cond-mat.stat-mech"
  ],
  "abstract": "We consider the steady state of an open system in which there is a flux of matter between two reservoirs at different chemical potentials. For a large system of size $N$, the probability of any macroscopic density profile $\\rho(x)$ is $\\exp[-N{\\cal F}(\\{\\rho\\})]$; ${\\cal F}$ thus generalizes to nonequilibrium systems the notion of free energy density for equilibrium systems. Our exact expression for $\\cal F$ is a nonlocal functional of $\\rho$, which yields the macroscopically long range correlations in the nonequilibrium steady state previously predicted by fluctuating hydrodynamics and observed experimentally.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2001-09-19T16:05:20.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "free energy functional",
      "nonequilibrium systems",
      "exactly solvable case",
      "nonequilibrium steady state",
      "macroscopically long range correlations"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Phys. Rev. Lett."
    },
    "note": {
      "typesetting": "RevTeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}