2023/02/26 by Paul Zeiger, Jordan A. Hachtel, Zeiger, Paul +13
Engineering · Physics and Astronomy · #Acoustic Wave Resonator Technologies #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mechanical and Optical Resonators #Terahertz technology and applications
paper · pdf · doi:10.48550/arxiv.2302.13415
openalex publication_date 2023/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The isotopic mass of constituent elements of materials has a well-known effect on the energy of vibrational modes. By means of monochromated scanning transmission electron microscopy we have experimentally studied the phonon bandstructure of hexagonal BN, where a phonon band gap appears between in-plane optical phonon modes and the lower energy part of the phonon spectrum. The size of the phonon band gap can be manipulated by the isotopic mass of the boron. While in 11BN the phonon band gap is about 7 meV wide, in 10BN the gap nearly closes, being an order of magnitude smaller (below 0.5 meV). This opens exciting options for manipulating terahertz wave propagation through isotopically structured devices having otherwise no interfaces between chemically distinct components.