We show that surface plasmons of a two-dimensional Dirac metal such as graphene can be reflected by line-like perturbations hosting one-dimensional electron states. The reflection originates from a strong enhancement of the local optical conductivity caused by optical transitions involving these bound states. We propose that the bound states can be systematically created, controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared nanoimaging, we obtain experimental evidence for the locally enhanced conductivity of graphene induced by a carbon nanotube gate, which supports this theoretical concept.
@article{arxiv.1602.03232,
title = {Tunable plasmonic reflection by bound 1D electron states in a 2D Dirac metal},
author = {Bor-Yuan Jiang and Guangxin Ni and Cheng Pan and Zhe Fei and Bin Cheng and Chun Ning Lau and Marc Bockrath and Dimitri N. Basov and Michael M. Fogler},
journal= {arXiv preprint arXiv:1602.03232},
year = {2016}
}