Graphene-based heterostructures display a variety of phenomena that are strongly tunable by electrostatic local gates. Monolayer graphene (MLG) exhibits tunable surface plasmon polaritons, as revealed by scanning nano-infrared experiments. In bilayer graphene (BLG), an electronic gap is induced by a perpendicular displacement field. Gapped BLG is predicted to display unusual effects such as plasmon amplification and domain wall plasmons with significantly larger lifetime than MLG. Furthermore, a variety of correlated electronic phases highly sensitive to displacement fields have been observed in twisted graphene structures. However, applying perpendicular displacement fields in nano-infrared experiments has only recently become possible (Ref. 1). In this work, we fully characterize two approaches to realizing nano-optics compatible top-gates: bilayer MoS2 and MLG. We perform nano-infrared imaging on both types of structures and evaluate their strengths and weaknesses. Our work paves the way for comprehensive near-field experiments of correlated phenomena and plasmonic effects in graphene-based heterostructures.
@article{arxiv.2011.10198,
title = {Dual-gated graphene devices for near-field nano-imaging},
author = {Sai S. Sunku and Dorri Halbertal and Rebecca Engelke and Hyobin Yoo and Nathan R. Finney and Nicola Curreli and Guangxin Ni and Cheng Tan and Alexander S. McLeod and Chiu Fan Bowen Lo and Cory R. Dean and James C. Hone and Philip Kim and Dmitri N. Basov},
journal= {arXiv preprint arXiv:2011.10198},
year = {2021}
}