Remote heat dissipation in atom-sized contacts

Understanding and control of heat dissipation is an important challenge in nanoelectronics wherein field-accelerated hot carriers in current-carrying ballistic systems release a large part of the kinetic energy into external bulk phonon baths. Here we report on a physical mechanism of this remote heat dissipation and its role on the stability of atomic contacts. We used a nano-fabricated thermocouple to directly characterize the self-heating in a mechanically-configurable Au junction. We found more pronounced heat dissipation at the current downstream that signifies the electron-hole asymmetry in Au nanocontacts. Meanwhile, the simultaneously measured single-atom chain lifetime revealed a minor influence of the heat dissipation on the contact stability by virtue of microleads serving as an effective heat spreader to moderate the temperature rise to several Kelvins from the ambient under microwatt input power. The present finding can be used for practical design of atomic and molecular electronic devices for heat dissipation managements.