Observation of Boundary‐Obstructed Topological Insulators in 2D Asymmetric Su–Schrieffer–Heeger Topological Electric Circuits

Abstract

Topological insulators that support unique symmetry‐protected boundary states gain popularity in the field of electric circuit systems. Boundary‐obstructed topological (BOT) insulators, as a new class of topological insulators, do not utilize the closure of the bulk band during the topological phase transition, which displays as an obstruction of boundary states. In this work, the experimental realization of BOT insulators based on electric circuit systems are reported and it is further demonstrated experimentally that the corresponding hollow structure consisting of only edges and corners can offer corner states in the edge gap. In this research, a highly controllable platform is offered for investigating unique topological phenomena and the way is paved for observing boundary‐obstructed topology by electric circuit systems.