****TECHNICAL ABSTRACT**** This award supports the construction and study of thermal radiators that contain millions of atoms but are small in comparison to a typical thermal wavelength, using filaments constructed with carbon nanotubes, graphene, and tungsten nanowires. Incandescent radiators in this size regime operate in an area that is wholly in neither the quantum mechanical nor the thermodynamic limit. This investigation will require an improved understanding of thermal transport in extreme temperature gradients at the nanoscale. Combining microfabricated devices and transmission electron microscopy characterization, these studies will extend unique imaging single-color pyrometry techniques and complement them with time-correlated single photon counting (TCSPC) correlation measurements. Because the nanolamps are approximately black and operate in the same exotic size-to-wavelength regime, benchmarking their coherence properties may provide further insight into the quantum physics of black holes and Hawking radiation. This project will support the training of a PhD student, who will necessarily master a wide array of skills in critical areas on the technological frontier, including microfabrication, electronics integration, and nanomaterials.
This award supports the construction and study of tiny incandescent lamps. The nanolamps have carbon filaments much like those originally used by Edison, but a billion times smaller. A typical incandescent lamp has dimensions that are large in comparison to the wavelengths of the light that it emits. Only recently has microfabrication technology advanced to the point where it is now possible to build "small" lamps that operate in the opposite limit and emit easily detected optical photons. The study of such lamps will probe the mechanisms of heat transport in devices where the temperature changes by thousands of degrees on sub-micrometer length scales. Furthermore, small lamps are ideal for elucidating the coherence properties of thermal radiation, which contrary to the common misconception, is not completely incoherent. New measurements of incandescent radiation in this unexplored regime will improve the current understanding heat transport at small length scales, the coherence properties of thermal photons, and the relationships between quantum mechanics and thermodynamics. Such measurements may even shed light on the physics of black holes, which are also thought to be "small" in comparison to the thermal Hawking radiation that they emit. This project will support the training of a PhD student, who will necessarily master a wide array of skills in critical areas on the technological frontier, including microfabrication, electronics integration, and nanomaterials.
