title: Heat transport through a solid-solid junction: the interface as an autonomous thermodynamic system.
abstract: We perform computational experiments using nonequilibrium molecular dynamics simulations, showing that the interface between two solid materials can be described as an autonomous thermodynamic system. We verify the local equilibrium and give support to the Gibbs description of the interface also away from the global equilibrium. In doing so, we reconcile the common formulation of the thermal boundary resistance as the ratio between the temperature discontinuity at the interface and the heat flux with a more rigorous derivation from nonequilibrium thermodynamics. We also show that thermal boundary resistance of a junction between two pure solid materials can be regarded as an interface property, depending solely on the interface temperature, as implicitly assumed in some widely used continuum models, such as the acoustic mismatch model. Thermal rectification can be understood on the basis of different interface temperatures for the two flow directions.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) Campus de Bellaterra, 08193 Bellaterra, Barcelona, Spain. rrurali@icmab.es.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Rurali
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) Campus de Bellaterra, 08193 Bellaterra, Barcelona, Spain. rrurali@icmab.es and Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria, I-09042 Monserrato (Ca), Italy and Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
authors.forename: Luciano
authors.initials: L
authors.lastname: Colombo
authors.affiliation: Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Cartoixà
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. signe.kjelstrup@ntnu.no and SINTEF Energy Research, NO-7465 Trondheim, Norway.
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Wilhelmsen
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. signe.kjelstrup@ntnu.no.
authors.forename: Thuat T
authors.initials: TT
authors.lastname: Trinh
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. signe.kjelstrup@ntnu.no.
authors.forename: Dick
authors.initials: D
authors.lastname: Bedeaux
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. signe.kjelstrup@ntnu.no.
authors.forename: Signe
authors.initials: S
authors.lastname: Kjelstrup