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

TL;DR

This paper investigates microwave edge plasmons in quantum anomalous Hall materials, revealing dissipation mechanisms and their impact on edge state propagation, which is vital for future quantum and microwave device applications.

Contribution

It provides the first detailed analysis of edge plasmon dissipation in V-doped QAH materials, highlighting charge puddle interactions as a key dissipation source.

Findings

Charge puddles significantly contribute to dissipation.

Microwave transmission varies with doping and temperature.

Understanding dissipation aids in improving QAH device performance.

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 $\mathrm{(Bi_xSb_\text{1-x})_2Te_3}$, the understanding of their dissipation remains incomplete. Our study explores edge plasmon dissipation in V-doped $\mathrm{(Bi_xSb_\text{1-x})_2Te_3}$ 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.