Two-channel thermal transport and high-order phonon coupling in solids
Thermal transport property of materials is of critical significance for a range of technologically important applications, such as thermoelectrics and thermal barrier coatings. The propagation of particle-like phonons usually dominates the thermal transport of semiconducting and insulating solids; however, recent studies show that diffusive thermal transport can become the predominant term in anharmonic crystals with strong phonon coherence. Therefore, the computation of two-channel thermal transport is paramount for accurate prediction of the lattice thermal conductivity. Different theoretical approaches have been proposed in the past years for calculating the diffusive channel of thermal transport, while phonon frequencies and lifetimes are usually taken as the inputs. In this presentation, the importance of anharmonic phonon coupling on the phonon properties and thermal conductivity of solids will be discussed. Different levels of computational methods based on perturbation theory and molecular dynamics simulations are applied for deeper insight into the lattice thermal transport of solids.
Dr Chen studied at Oxford University and Beihang University, and received his PhD degree in 2010. After completing his postdoctoral training at Columbia University in the City of New York, he joined The University of Hong Kong as an Assistant Professor in 2014, being promoted to Associate Professor in 2020. Dr Chen’s research focuses on the materials physics for electrical and thermal transports, such as electronic structures and lattice dynamics. He has authored more than 140 peer-reviewed journal publications and presented invited papers around the globe. He received an Outstanding Young Researcher Award from The University of Hong Kong in 2020.