M. Esmann, F.R. Lamberti, P. Senellart, I. Favero, O. Krebs, L. Lanco, C. Gomez Carbonell, A. Lemaître, and N.D. Lanzillotti-Kimura
Phys. Rev. B 97, 155422 – Published 19 April 2018

The authors introduce the concept of topological invariants to nanophononics and experimentally implement a nanophononic system supporting a robust topological interface state at 350 GHz. The state is constructed through band inversion, i.e., by concatenating two GaAlAs semiconductor superlattices with inverted spatial mode symmetries. The authors experimentally evidence this topological mode through Raman spectroscopy.