Capacitance sensing in bilayer graphene with gate reflectometry
Abstract
In the search for topological states in bilayer graphene, capacitance measurement methods are widely utilized in bridge type readouts or source-drain reflectometry setups. In this paper we demonstrate an alternative readout method based on gate reflectometry. We probe the capacitance of a BLG flake encapsulated between hBN and WSe2 through a lumped-element LC resonator coupled to the top gate electrode of the heterostructure. The microwave readout reliably tracks the opening of a displacement field-induced band gap in the device. Compared to simultaneous DC transport measurements, the RF signal proves to be less affected by the percolating transport channels caused by sample disorder. Furthermore, we use the gate based readout to identify a small-angle alignment between the hBN and BLG flake. From the fixed frequency microwave readout, we extract the device capacitance change between the insulating and metallic state of the bilayer and utilize a comprehensive capacitance network model to explain its origin. Finally, we propose an advanced, multiplexed double-resonator readout scheme capable of simultaneously measuring top and bottom gate capacitances to extract the layer polarizability of the system. This work establishes gate reflectometry as a highly scalable and powerful methodology for exploring topological phases and internal charge dynamics in van der Waals heterostructures.
Related
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BibTeX
@misc{kalmar2026capacitance,
title = {{Capacitance sensing in bilayer graphene with gate reflectometry}},
author = {Tamás Kalmár and Gergő Fülöp and Bálint Szentpéteri and Olivér Kürtössy and Kenji Watanabe and Takashi Taniguchi and Szabolcs Csonka and Péter Makk},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35125},
eprint = {2609.35125},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35125},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Capacitance sensing in bilayer graphene with gate reflectometry
AU - Tamás Kalmár
AU - Gergő Fülöp
AU - Bálint Szentpéteri
AU - Olivér Kürtössy
AU - Kenji Watanabe
AU - Takashi Taniguchi
AU - Szabolcs Csonka
AU - Péter Makk
PY - 2026
DA - 2026/09/30
PB - arXiv
DO - 10.48550/arxiv.2609.35125
UR - https://arxiv.org/abs/2609.35125
AB - In the search for topological states in bilayer graphene, capacitance measurement methods are widely utilized in bridge type readouts or source-drain reflectometry setups. In this paper we demonstrate an alternative readout method based on gate reflectometry. We probe the capacitance of a BLG flake encapsulated between hBN and WSe_2 through a lumped-element LC resonator coupled to the top gate electrode of the heterostructure. The microwave readout reliably tracks the opening of a displacement field-induced band gap in the device. Compared to simultaneous DC transport measurements, the RF signal proves to be less affected by the percolating transport channels caused by sample disorder. Furthermore, we use the gate based readout to identify a small-angle alignment between the hBN and BLG flake. From the fixed frequency microwave readout, we extract the device capacitance change between the insulating and metallic state of the bilayer and utilize a comprehensive capacitance network model to explain its origin. Finally, we propose an advanced, multiplexed double-resonator readout scheme capable of simultaneously measuring top and bottom gate capacitances to extract the layer polarizability of the system. This work establishes gate reflectometry as a highly scalable and powerful methodology for exploring topological phases and internal charge dynamics in van der Waals heterostructures.
ER -