Abstract:
Thermal transport is typically an incoherent process. However, for nanostructures with feature sizes smaller than the mean free paths of thermal carriers, thermal transport becomes coherent. Many thermal characteristics are enhanced in the coherent transport regime, since thermal transfer is determined by various wave mechanisms that are unattainable in the conventional incoherent process.
In particular, coherent transport is readily realizable when photon is the main thermal carrier, because of its weak nonlinearity and interactions. In this talk, we will see how photonic band gaps arising from multilayer photonic crystals can be exploited to suppress thermal conductance below that of vacuum, thus enabling extreme thermal insulation. We will further identify the universal limit of such conductance suppression, and its theoretical implications in relation to the statistical features of photonic bands distribution in frequency domain.
Lastly, we will address the issue of thermal emission, specifically, the role of guided wave resonances in enhancing near-field spatial coherence of emitted thermal fields, and the potential in realizing thermal antennas.
Coffee and tea will be served 20 minutes prior to the seminar.