Ultrafast evanescent heat transfer across solid interfaces via hyperbolic phonon-polariton modes in hexagonal boron nitride.

ABSTRACT: Thermal transport across solid-solid interfaces is vital for advanced electronic and photonic applications, yet conventional conduction pathways often restrict performance. In polar crystals, hybridized vibrational modes called phonon polaritons offer a promising avenue to overcome the limitations of intrinsic phonon heat conduction. Here our work demonstrates that volume-confined hyperbolic phonon polariton (HPhP) modes can transfer energy across solid-solid interfaces at rates far exceeding phonon-phonon conduction. Using pump-probe thermoreflectance with a mid-infrared, tunable probe pulse with subpicosecond resolution, we remotely and selectively observe HPhP modes in hexagonal boron nitride (hBN) via broadband radiative heating from a gold source. Our measurements ascertain that hot e

SUBMITTER: Hutchins W 

PROVIDER: S-EPMC12048350 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature