Thermal transport in individual atomic junctions and chains is of great fundamental interest due to unique quantum effects expected to arise in them. Here, by employing novel, custom-fabricated, picowatt-resolution calorimetric scanning probes, we measure the thermal conductance of gold and platinum metallic wires down to single-atom junctions. Our work reveals that the thermal conductance of gold single atom junctions is quantized at room temperature and shows that the Wiedemann-Franz law relating thermal and electrical conductance is satisfied even in single-atom contacts. Furthermore, we quantitatively explain our experimental results within the Landauer picture for quantum thermal transport. The experimental techniques reported here will enable thermal transport studies in atomic and molecular chains, which is key to investigating numerous fundamental issues that have remained experimentally inaccessible.
Longji Cui, Wonho Jeong, Sunghoon Hur, Manuel Matt, Jan C. Klöckner, Fabian Pauly, Peter Nielaba, Juan Carlos Cuevas, Edgar Meyhofer, Pramod Reddy