Heat transport through atomic contacts

Heat transport measurements in single-atom junctions verify the proportionality between thermal and electrical conductance. Heat transport and dissipation at the nanoscale severely limit the scaling of high-performance electronic devices and circuits 1 . Metallic atomic junctions serve as model systems to probe electrical and thermal transport down to the atomic level as well as quantum effects that occur in one-dimensional (1D) systems 2 . Whereas charge transport in atomic junctions has been studied intensively in the past two decades 2 , 3 , 4 , 5 , heat transport remains poorly characterized because it requires the combination of a high sensitivity to small heat fluxes and the formation of stable atomic contacts. Here we report heat-transfer measurements through atomic junctions and analyse the thermal conductance of single-atom gold contacts at room temperature. Simultaneous measurements of charge and heat transport reveal the proportionality of electrical and thermal conductance, quantized with the respective conductance quanta 6 . This constitutes a verification of the Wiedemann–Franz law at the atomic scale 7 .