Electron transport in bilayer graphene nanoconstrictions patterned using atomic force microscope nanolithography

Published

March 20, 2025

Author(s)

Robert Rienstra, Nishat Sultana, En-Min Shih, Evan Stocker, Kenji Watanabe, Takashi Taniguchi, Curt Richter, Joseph Stroscio, Nikolai Zhitenev, Fereshte Ghahari Kermani

Abstract

Here we report on low temperature transport measurements of encapsulated bilayer graphene nano constrictions fabricated employing electrode-free AFM-based local anodic oxidation (LAO) nanolithography. This technique allows for the creation of constrictions as narrow as 20 nm. While larger constrictions exhibit an enhanced energy gap, single quantum dot (QD) formation is observed within smaller constrictions with addition energies exceeding 100 meV, which surpass previous experiments on patterned QDs. These results suggest that transport through these narrow constrictions is governed by edge disorder combined with quantum confinement effects. Our findings introduce electrode-free AFM-LAO lithography as an easy and flexible method for creating nanostructures with tunable electronic properties without relying on patterning techniques such as e-beam lithography. The excellent control and reproducibility provided by this technique opens exciting opportunities for carbon-based quantum electronics and spintronics.

Citation

Physical Review B

Volume

111

Issue

11

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevB.111.115145

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Keywords

Bilayer Graphene, AFM-LAO lithography, Constriction, Quantum dot, low temperature transport

Citation

Rienstra, R. , Sultana, N. , Shih, E. , Stocker, E. , Watanabe, K. , Taniguchi, T. , Richter, C. , Stroscio, J. , Zhitenev, N. and Ghahari Kermani, F. (2025), Electron transport in bilayer graphene nanoconstrictions patterned using atomic force microscope nanolithography, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.111.115145, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959067 (Accessed April 19, 2025)