Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
Science. 2017 Mar 17;355(6330):1192-1195. doi: 10.1126/science.aam6622. Epub 2017 Feb 16.
Thermal transport in individual atomic junctions and chains is of great fundamental interest because of the distinctive quantum effects expected to arise in them. By using novel, custom-fabricated, picowatt-resolution calorimetric scanning probes, we measured 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 framework for quantum thermal transport. The experimental techniques reported here will enable thermal transport studies in atomic and molecular chains, which will be key to investigating numerous fundamental issues that thus far have remained experimentally inaccessible.
在单个原子结和链中，热传输具有重要的基础性研究意义，因为在这些结构中有望出现独特的量子效应。我们利用新颖的、定制的、皮瓦分辨率量热扫描探针，将金和铂金属线的热导测量降低到单原子结。我们的工作表明，金单原子结的热导在室温下是量子化的，并表明即使在单原子接触中，热和电导率之间的维德曼-弗朗兹定律也得到了满足。此外，我们在量子热传输的朗道框架内定量解释了我们的实验结果。这里报道的实验技术将使原子和分子链中的热传输研究成为可能，这对于研究迄今为止在实验上无法触及的许多基本问题至关重要。
