We propose a realization of perfect valley filters based on the chiral domain-wall channels between a quantum anomalous Hall insulator and a quantum valley Hall insulator. Uniquely, all these channels reside in the same valley and propagate unidirectionally, 100% valley-polarizing passing-by carriers without backscattering. The valley index, the chirality, and the number of the channels are protected by topological charges, controllable by external fields, and detectable by circular dichroism.
Cite
@article{arxiv.1501.00114,
title = {Perfect Valley Filter in Topological Domain Wall},
author = {Hui Pan and Xin Li and Fan Zhang and Shengyuan A. Yang},
journal= {arXiv preprint arXiv:1501.00114},
year = {2015}
}