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arXiv · 1106.5822

Many-body interactions in quasi-freestanding graphene

David A. Siegel·Cheol-Hwan Park·Choongyu Hwang·Jack Deslippe·Alexei V. Fedorov·Steven G. Louie·Alessandra Lanzara
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Abstract

The Landau-Fermi liquid picture for quasiparticles assumes that charge carriers are dressed by many-body interactions, forming one of the fundamental theories of solids. Whether this picture still holds for a semimetal like graphene at the neutrality point, i.e., when the chemical potential coincides with the Dirac point energy, is one of the long-standing puzzles in this field. Here we present such a study in quasi-freestanding graphene by using high-resolution angle-resolved photoemission spectroscopy. We see the electron-electron and electron-phonon interactions go through substantial changes when the semimetallic regime is approached, including renormalizations due to strong electron-electron interactions with similarities to marginal Fermi liquid behavior. These findings set a new benchmark in our understanding of many-body physics in graphene and a variety of novel materials with Dirac fermions.

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David A. Siegel, Cheol-Hwan Park, Choongyu Hwang, Jack Deslippe, Alexei V. Fedorov, Steven G. Louie, Alessandra Lanzara. 2011-06-28. Many-body interactions in quasi-freestanding graphene. https://doi.org/10.1073/pnas.1100242108

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