Three-dimensional vectorial imaging of surface phonon polaritons

Abstract

Mapping nanostructure surface excitations Atomic vibrations (phonons) govern many physical properties of materials, especially those related to heat and thermal transport. They also provide fingerprints of the chemistry of a wide variety of materials, from solids to molecules. The behavior of phonons in nanostructures can be appreciably modified because of confinement effects. Li et al. combined several electron microscopy techniques to map out the phonon-polariton excitations across the surface of magnesium oxide nanostructures with high spatial, spectral, and angular resolution. The reconstruction of the surface excitation maps in three dimensions will be useful for understanding and optimizing the properties of the nanostructured materials for advanced functionality. Science , this issue p. 1364