Nanoscale Heat Transport

When the characteristic length of a material approaches its dominant phonon mean-free-path, ballistic effects become important and standard diffusive theory is no longer applicable. On the other hand, the phonon Boltzmann Transport Equation (BTE) captures the interaction between phonons and the boundary of the material, but at the expense of computational effort. Currently, I am working on developing an efficient, parallel code that solves the BTE for anisotropic Brillouin zones, three-dimensional geometries and with input data computed by first-principles calculations.

Nanostructured Thermoelectrics

A thermoelectric material must have good electrical conductivity and poor thermal conductivity, a requirement that is rarely encountered in nature. For this reason, the conversion efficiency of natural compounds is relatively small compared to that of traditional technologies. Thanks to their ability to decouple their electrical and thermal properties, nanostructures are potential candidates for high-efficiency thermoelectric materials. Presently, I am investigating thermal transport in complex nanoporous materials, a promising material platform that is currently within experimental reach.

Atomistic-to-continuum coupling

It is crucial to any simulations to find a trade-off between accuracy and computational demand. On one side, continuum models, e.g. finite elements, provide a flexible and relatively affordable description of matter at the macroscale. On the other hand, however, such models do not take into account the natural discretization of Nature, namely atoms. Thankfully, in many cases, the atomistic description of a material, which is computationally expensive, is needed only in some spatial region. Building models that effectively bridge these two level of accuracy would enable accurate yet affordable simulations of complex devices.