Momentum microscopy of Pb-intercalated graphene on SiC: charge neutrality and electronic structure of interfacial Pb

Abstract

Intercalation is an established technique for tailoring the electronic structure of epitaxial graphene. Moreover, it enables the synthesis of otherwise unstable two-dimensional (2D) layers of elements with unique physical properties compared to their bulk versions due to interfacial quantum confinement. In this work, we present uniformly Pb-intercalated quasi-freestanding monolayer graphene on SiC, which turns out to be essentially charge neutral with an unprecedented $p$-type carrier density of only $(5.5\pm 2.5)\times 10^9$ cm${}^{-2}$. Probing the low-energy electronic structure throughout the entire first surface Brillouin zone by means of momentum microscopy, we clearly discern additional bands related to metallic 2D-Pb at the interface. Low-energy electron diffraction further reveals a $10\times 10$ Moiré superperiodicity relative to graphene, counterparts of which cannot be directly identified in the available band structure data. Our experiments demonstrate 2D interlayer confinement and associated band structure formation of a heavy-element superconductor, paving the way towards strong spin-orbit coupling effects or even 2D superconductivity at the graphene/SiC interface.

11 pages, 4 figures (& 1 page Supplemental Material, 2 figures)

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• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
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• Fermi velocity engineering in graphene by substrate modification
• Many-body interactions in quasi-freestanding graphene
• Overdoping graphene beyond the van Hove singularity
• Rashba type spin-orbit splitting of quantum well states in ultrathin Pb films
• Competing orders at higher-order Van Hove points
• Scattering resonances in graphene
• Core-level spectra from graphene
• Momentum-Space Spin Antivortex and Spin Transport in Monolayer Pb
• Suppression of electron scattering resonances in graphene by quantum dots

Cited by in corpus (6)

• Large-Area Intercalated 2D-Pb/Graphene Heterostructure as a Platform for Generating Spin-Orbit Torque
• Strain-modulated Intercalated Phases of Pb Monolayer with Dual Periodicity in SiC(0001)-Graphene Interface
• Fano physics behind the N-resonance in graphene
• Pb-intercalated epitaxial graphene on SiC: Full insight into band structure and orbital character of interlayer Pb, and charge transfer into graphene
• Charge transfer between van der Waals coupled metallic 2D layers
• Defect-Mediated Phase Engineering of 2D Ag at the Graphene/SiC Interface