Atomic heat transfer in nanoscale contacts mediated by van der Waals interactions

Van der Waals-interfacial heat transfer is a key element in thermal problems in atomic-scale devices including quantum computing devices, solid-state batteries, and solar power generation devices. However, its characterization remains challenging due to the lack of atomic-scale measurement technologies. Here, we use custom-fabricated scanning probes with embedded highly precise thermometers and an atomic milling technique to simultaneously measure heat transfer and the van der Waals interactions at atomic contacts. Experimental results indicate the transformation of the heat transfer mechanism with increasing van der Waals atomic interactions. We identify the transition from single-atomic to multi-atomic channel mediated heat transfer through analysis using the Rabinovich model together with molecular dynamics simulations. Additionally, we confirm the same transition mechanism in various van der Waals interfaces and identify differences in their interfacial regions. This work provides an experimental framework and insights for understanding van der Waals-interfacial heat transfer. Van der Waals-interfacial heat transfer is crucial for optimizing thermal management in atomic-scale devices, yet its characterization is hindered by measurement challenges. Here, the authors employ custom scanning probes and atomic milling to reveal a transition from single-atomic to multi-atomic channel heat transfer, offering a framework for improved thermal design in advanced technologies.