High-yield fabrication of bubble-free magic-angle twisted bilayer graphene devices with high twist-angle homogeneity
Journal article, 2025
Magic-angle twisted bilayer graphene (MATBG) is a very versatile material, hosting a wide variety of exotic phases while allowing easy tunability of material parameters. However, the fabrication of MATBG devices remains a challenging and inefficient manual process, with device properties being highly dependent on the specific fabrication methods, often resulting in inconsistency and variability. Here we present an optimized protocol for the fabrication of MATBG samples, using deterministic graphene anchoring to stabilize the twist angle and a careful bubble-removal technique to ensure high twist-angle homogeneity. We use low-temperature transport experiments to extract the average twist angle between pairs of leads. We find that up to ∼38% of the devices show μm2-sized regions with twist angles in the range of θ = 1.1 ± 0.1° and twist-angle variations of Δθ ≤ 0.02°. In some instances, such regions were up to 36 μm2 large. The discussed protocols may be directly transferred to non-graphene materials and will be useful for the growing field of moiré materials.
2D materials
superconductivity
device fabrication
magic-angle twisted bilayer graphene
moiré materials
Author
Jaime Díez-Mérida
MCQST
Institut de Ciencies Fotoniques
Ludwig Maximilian University of Munich (LMU)
Ipsita Das
MCQST
Ludwig Maximilian University of Munich (LMU)
Giorgio Di Battista
Ludwig Maximilian University of Munich (LMU)
MCQST
Andrés Díez-Carlón
Ludwig Maximilian University of Munich (LMU)
MCQST
Martin Lee
Ludwig Maximilian University of Munich (LMU)
MCQST
Lunjie Zeng
Chalmers, Physics, Nano and Biophysics
Kenji Watanabe
National Institute for Materials Science (NIMS)
Takashi Taniguchi
National Institute for Materials Science (NIMS)
Eva Olsson
Chalmers, Physics, Nano and Biophysics
Dmitri K. Efetov
Ludwig Maximilian University of Munich (LMU)
MCQST
Newton
29506360 (eISSN)
Vol. 1 1 100007ARTEMI - a National Research Infrastructure in Electron Microscopy
Swedish Foundation for Strategic Research (SSF) (RIF21-0026), 2022-09-01 -- 2027-12-31.
Swedish Research Council (VR) (2021-00171), 2022-01-01 -- 2026-12-31.
Plasmon-exciton coupling at the attosecond-subnanometer scale: Tailoring strong light-matter interactions at room temperature
Knut and Alice Wallenberg Foundation (2019.0140), 2020-07-01 -- 2025-06-30.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Condensed Matter Physics
Other Physics Topics
DOI
10.1016/j.newton.2024.100007