Understanding Thermal Transport for Electronics, Energy, Quantum, and Space Applications

A solid understanding of thermal transport is crucial to advancements in microelectronics cooling, thermal energy conversion, quantum computing, and space exploration. In this talk, I will present our contributions to the field by integrating bleeding-edge modeling and experimental approaches: (1) Microelectronics cooling. We derived an anharmonic atomistic Green’s function formalism that solves a long-standing challenge in thermal interface modeling. We carried out the first E-field-dependent thermal conductivity measurements in ultrawide bandgap semiconductors up to breakdown voltage and developed a new computational framework to study the non-equilibrium phonon transport under E-field. (2) Thermoelectric Energy Conversion. We uncovered the secrets behind the ultralow thermal conductivity in hybrid perovskites using inelastic X-ray scattering measurements. We solved the mystery of GeTe’s anomalous increasing lattice thermal conductivity across the phase transition using machine-learning assisted first-principles calculations. (3) Quantum Computing. We developed a full ab initio scheme to calculate non-equilibrium, mode-dependent quasiparticle-phonon dynamics in superconductors, revealing key impacts on qubit performance. (4) Space exploration. We created a synthesis routine for polymer composites and achieved record-high thermal conductivity for high-voltage insulation, paving the way for a sustainable lunar electrical grid.