Description
Two dimensional (2D) van der Waals heterostructures offer an unprecedented platform to engineer heat flow by design. Weak interlayer coupling, strong elastic anisotropy, and highly structured phonon dispersions produce thermal transport that is fundamentally different from 3D crystals. In this talk, I will outline a phonon engineering framework for 2D stacks that link atomic structure to spectral energy transfer. I will first clarify the governing mechanisms for in plane and cross plane thermal transport in layered materials, emphasizing the roles various phonon modes and classification between coherent and incoherent phonon propagation. Building on this foundation, I will show how heterostructure design knobs—layer sequence and thickness, twist angle and moiré periodicity, strain and intercalation—permit selective filtering and blocking of phonons. A spectral perspective, using modal-resolved thermal conductivity and wavevector-resolved interfacial thermal conductance, will be used to illustrate phonon band engineering. Finally, I will discuss the challenges and opportunities for thermal management in next the generation electronics with particular focus on cryo-CMOS devices.
