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

Abstract

The quantum anomalous Hall (QAH) effect, with its single chiral, topologically protected edge state, offers a platform for flying Majorana states as well as non-reciprocal microwave devices. While recent research showed the non-reciprocity of edge plasmons in Cr-doped $(\mathrm{B}{\mathrm{i}}_{\mathrm{x}}\mathrm{S}{\mathrm{b}}_{\text{1-x}}{)}_2\mathrm{T}{\mathrm{e}}_3$, the understanding of their dissipation remains incomplete. Our study explores edge plasmon dissipation in V-doped $(\mathrm{B}{\mathrm{i}}_{\mathrm{x}}\mathrm{S}{\mathrm{b}}_{\text{1-x}}{)}_2\mathrm{T}{\mathrm{e}}_3$ films, analyzing microwave transmission across various conditions. We identify interactions with charge puddles as a primary source of dissipation, providing insights critical for developing improved QAH-based technologies.

6 pages, 4, figures