Van-Nham Phan, Holger Fehske
We report a theoretical study of the many-body effects of electron-electron
interaction on the ground-state and spectral properties of bilayer graphene.
Using a projector-based renormalization method we show that if a finite voltage
difference is applied between the graphene layers electron-hole pairs can be
formed and---at very low temperatures---an excitonic instability might emerge
in a bilayer graphene structure. The single-particle spectral function near the
Fermi surface exhibits a prominent quasi-particle peak, different from neutral
(undoped) bilayer graphene. Away from the Fermi surface, we find that states
strongly interact with plasmons, thereby giving rise to a broad plasmaron peak
that explains prominent features of recent angle-resolved photoemission
spectroscopy data.
View original:
http://arxiv.org/abs/1202.0900
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