title: Nonequilibrium steady states in contact: approximate thermodynamic structure and zeroth law for driven lattice gases.
abstract: We explore driven lattice gases for the existence of an intensive thermodynamic variable which could determine "equilibration" between two nonequilibrium steady-state systems kept in weak contact. In simulations, we find that these systems satisfy surprisingly simple thermodynamic laws, such as the zeroth law and the fluctuation-response relation between the particle-number fluctuation and the corresponding susceptibility remarkably well. However, at higher densities, small but observable deviations from these laws occur due to nontrivial contact dynamics and the presence of long-range spatial correlations.
authors.affiliation: II. Institut für Theoretische Physik, Universität Stuttgart, Stuttgart 70550, Germany.
authors.forename: Punyabrata
authors.initials: P
authors.lastname: Pradhan
authors.forename: Christian P
authors.initials: CP
authors.lastname: Amann
authors.forename: Udo
authors.initials: U
authors.lastname: Seifert