Observation of the Hofstadter Butterfly and Topological Edge States in Reconfigurable Quasi-Periodic Acoustic Crystals,

X. Ni, K. Chen, M. Weiner, D. J. Apigo, C. Prodan, A. Alù, E. Prodan, and A. B. Khanikaev, Observation of the Hofstadter Butterfly and Topological Edge States in Reconfigurable Quasi-Periodic Acoustic Crystals, Communication Physics,  2, 55 (7), (2019).