Beamsplitter Benefits from Topological Antichiral Edge States

The proposed topological beamsplitter consists of two rectangular antichiral GPCs biased by opposite external magnetic fields. The antichiral GPCs exhibit antichiral edge states with opposite propagation directions. At the interface of the two GPCs, there is no edge state due to the presence of an armchair boundary. When an input source is placed at the center of the lower zigzag edge, the waves will be split into two beams propagating in opposite directions along the edge of the GPCs. The ratio between the right-to-left output beams can be adjusted by changing the incident angle of the excitation source.

The research was published in Opto-Electronic Science (www.doi.org/10.29026/oes.2022.220001).