Propagation, dissipation, and breakdown in quantum anomalous Hall edge states probed by microwave edge plasmons

The quantum anomalous Hall (QAH) effect, with its single chiral, topologically protected edge state, offers a platform for flying Majorana states as well as nonreciprocal microwave devices. While recent research showed the nonreciprocity of edge plasmons in Cr-doped (BixSb1−x)2Te3, the understanding of their dissipation remains incomplete. Our study explores edge plasmon dissipation in V-doped (BixSb1−x)2Te3 films, analyzing microwave transmission across various conditions. We identify interactions with charge puddles as a primary source, providing insights critical for developing improved QAH-based technologies. Published by the American Physical Society 2024