Emergent cavity junction around metal-on-graphene contacts

Fuente: arXiv
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Auteurs principaux: Zhao, Yuhao, Kapfer, Maëlle, Watanabe, Kenji, Taniguchi, Takashi, Zilberberg, Oded, Jessen, Bjarke S.
Format: Preprint
Publié: 2024
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author Zhao, Yuhao
Kapfer, Maëlle
Watanabe, Kenji
Taniguchi, Takashi
Zilberberg, Oded
Jessen, Bjarke S.
author_facet Zhao, Yuhao
Kapfer, Maëlle
Watanabe, Kenji
Taniguchi, Takashi
Zilberberg, Oded
Jessen, Bjarke S.
contents 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 transport 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 tunneling. 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 interfaces, opening new avenues for understanding and devising graphene-based electronic devices.
format Preprint
id arxiv_https___arxiv_org_abs_2408_10973
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Emergent cavity junction around metal-on-graphene contacts
Zhao, Yuhao
Kapfer, Maëlle
Watanabe, Kenji
Taniguchi, Takashi
Zilberberg, Oded
Jessen, Bjarke S.
Mesoscale and Nanoscale Physics
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 transport 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 tunneling. 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 interfaces, opening new avenues for understanding and devising graphene-based electronic devices.
title Emergent cavity junction around metal-on-graphene contacts
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2408.10973