Heat radiation at the nanoscale – Planck law and Stefan-Boltzmann law reloaded 10. December 2019 | 14:15 h - 15:45 h
The properties of thermal radiation close to the surface of a material can deviate drastically from the well-known textbook characteristics of blackbody radiation. For example, it has been shown that thermal radiation can be quasi-monochromatic in the near-field regime, and can exhibit relatively large correlation times and lengths. Moreover, Planck’s law is no longer applicable in its usual form and needs to be generalized. Even more astonishing is the fact that the Stefan-Boltzmann law does not constitute an upper limit for the power per unit area which can be transferred between two closely spaced bodies; instead, it can be surpassed by several
orders of magnitude.
In this talk, I will sketch recent experimental and theoretical advances achieved in the rapidly evolving field of nanoscale heat radiation. In particular, I will briefly discuss thermal imaging with near-field scanning thermal microscopes, peculiarities of thermal radiation between and inside of hyperbolic metamaterials, and the possibility to rectify and amplify the radiative heat flux with thermotronic devices such as diodes or transistors based on the phase-change material vanadium dioxide. Finally, if we have the time I will comment on theoretical predictions on circular heat flux in magneto-optical systems which are at the heart of the thermal Hall effect.
Lecturer
PD Dr. Svend-Age Biehs, Institut für Physik, Carl von Ossietzky Universität Oldenburg