Achieving reading–writing electromagnetic signal memory based on high-order topological state.

In order to achieve an optical signal memory device with read–write functions, a topological Su–Schrieffer–Heeger lattice is proposed. It is found that a transformation between a topological corner state and an edge state occurs under the magneto-optical effect. Without an external magnetic field, the electromagnetic (EM) signal is confined and stored at the corner, which realizes the writing process of a signal. When an external magnetic field is applied, the EM signal is released from the corner to the edge, which realizes the reading process of the signal. The result is expected to provide guidance for the design of high-performance reading–writing EM memories. [ABSTRACT FROM AUTHOR]