Maxim Gorlach

ITMO University, Russia

5 September 2023 Tue 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

The concepts of topology have a profound impact on physics research spanning the fields of condensed matter, photonics and acoustics and predicting topological states that provide unprecedented versatility in routing and control of waves of various nature. Higher-order topological insulators further expand this plethora of possibilities. Here, we put forward a novel class of two-dimensional multipolar higher-order topological insulators that arise due to the interference of the degenerate modes of the individual meta-atoms generalizing the mechanism of spin-orbit coupling in condensed matter systems. We prove that besides disorder-robust corner modes the multimode nature of the lattice also gives rise to flat bands and corner states with extreme localization. We support our predictions by assembling the designed structure, observing multipolar topological corner states and experimentally demonstrating their coherent control.

  1. multipole higher-order topology and flat bands in a multimode lattice