Heat Management in the Ballistic Limit at the nanoscale – HANIBAL

The manipulation of heat fluxes is possible by acting on the transport of phonons at the nanoscale in thermal metamaterials. This is one of the major challenges of the current small-scale energy management. In order to demonstrate innovative effects involving large phonon mean-free-paths and long phonon-wavelength, it is essential to develop ultra-sensitive thermal sensors with a large operation temperature range. We propose, as a first step, to develop innovative sensors having an outstanding power sensitivity, on the order of few tens of Zeptowatt. These sensors will be made under two complementary forms: one crystalline using silicon and one amorphous using silicon nitride. In a second step, aided by calculations of optimal designs, we will carry out heat transfer measurements by thermal conduction in periodic and aperiodic nonlinear nanostructures in order to effectively address the demonstration of engineered thermal properties. We will focus our modelling and experiments on two representative systems: phononic crystals and thermal rectifiers. Significant outcomes are expected regarding heat management at the nanoscale for instance in innovative device like Cryo-CMOS and energy harvester.