Recently, the research groups led by Professors Xin-Ye Zou and Jian-Chun Cheng from the School of Physics at Nanjing University have made new progress in the study of acoustic topological matter. By introducing multiple degenerate p orbitals into a three-dimensional acoustic Su-Schrieffer-Heeger model, the team experimentally realized an orbital-induced 3D ℤ-classified higher-order topological insulator without relying on long-range hopping, providing a new route for multidimensional wave manipulation and highly integrated acoustic devices. This work was published in Physical Review Letters, entitled 3D Z-Classified Higher-Order Topological Insulator Induced by Multiple Orbitals.

Schematic illustration of orbital-engineered 3D Z-classified higher-order topology in an acoustic system.

Publication link: https://journals.aps.org/prl/abstract/10.1103/74kx-xg78