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Description:

Harnessing graphene devices for applications relies on a comprehensive understanding of how to interact with them. Specifically, scattering processes at the interface with metallic contacts can induce reproducible abnormalities in measurements. Here, we report on emergent trans- port signatures appearing when contacting sub- micrometer high-quality metallic top contacts to graphene. Using electrostatic simulations and first- principle calculations, we reveal their origin: the contact induces an n-doped radial cavity around it, which is cooperatively defined by the metal- induced electrostatic potential and Klein tunnel- ing. This intricate mechanism leads to secondary resistance peaks as a function of graphene doping that decreases with increasing contact size. Interestingly, in the presence of a perpendicular magnetic field, the cavity spawns a distinct set of Landau levels that interferes with the Landau fan emanating from the graphene bulk. Essentially, an emergent ’second bulk’ forms around the contact, as a result of the interplay between the magnetic field and the contact-induced electrostatic potential. The interplay between the intrinsic and emergent bulks leads to direct observation of bulk-boundary correspondence in our experiments. Our work unveils the microscopic mechanisms manifesting at metal-graphene inter- faces, opening new avenues for understanding and devising graphene-based electronic devices.

Rights:

• Creative Commons BY-NC-ND Attribution-NonCommercial-NoDerivs 4.0 International
  

Keyword: metal-graphene contacts, cavity junction, Klein tunneling


Date published: 2025-05-20

Publisher: American Chemical Society (ACS)

Journal:

• ACS Nano (ISSN: 19360851) vol. 19 issue. 19 p. 18156-18163

Funding:

• Energy Frontier Research Centers DE-SC0019443
• Eidgen?ssische Technische Hochschule Z?rich ETH-28 23-1
• Deutsche Forschungsgemeinschaft 449653034
• Core Research for Evolutional Science and Technology JPMJCR24A5
• Novo Nordisk Fonden NNF23OC0084494
• Villum Fonden
• JSPS KAKENHI 21H05233
• JSPS KAKENHI 23H02052

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1021/acsnano.4c16191

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Updated at: 2026-02-17 12:30:10 +0900

Published on MDR: 2026-02-17 09:11:02 +0900