Imaging valley-vortex edge modes in a phononic crystal at ultrahigh frequencies

作者：Paul H. Otsuka, Motonobu Tomoda, Daiki Hatanaka, Hiroshi Yamaguchi, Kenji Tsuruta, Osamu Matsuda · 发表于：Journal of Applied Physics · 年份：2025 · DOI：10.1063/5.0273147 · 被引用次数：2 · 研究领域：Topological Materials and Phenomena、Acoustic Wave Phenomena Research、Ultrasonics and Acoustic Wave Propagation

We perform optical measurements and numerical simulations of guided phonon propagation in novel topological phononic crystal structures at ultrahigh frequencies. The structures support valley-polarized states that exhibit an energy vortex nature and propagate with high efficiency at domain boundaries because backscattering is suppressed due to conservation of time reversal symmetry. We extract frequency- and time-resolved spatial mode patterns and k-space images, together with dispersion relations. We investigate the conditions required for robust propagation along interfaces and thereby observe very high efficiency waveguiding.