Observation of the corner state in three-dimensional pyrochlore topological electric circuits

Abstract

Abstract Topological circuits become a powerful platform for realizing and observing topological states with significant flexibility and tunability. In this work, we experimentally realized three-dimensional pyrochlore topological circuits with a third-order topological corner state. The generalized chiral symmetry enables the corner state to exist in the band gap or the continuum, and the corner state in our circuits is localized on a single corner due to passing through the Wannier center. Our work provides a paradigm for exploring various topological phenomena in higher-dimensional systems by using topological circuits, which may have potential applications in the fields of future communication and signal processing.