Electron interactions in bilayer graphene: Marginal Fermi liquid and zero-bias anomaly
Author(s)
Nandkishore, Rahul Mahajan; Levitov, Leonid
DownloadNandkishore-2010-Electron interaction.pdf (250.5Kb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Terms of use
Metadata
Show full item recordAbstract
We analyze the many-body properties of bilayer graphene (BLG) at charge neutrality, governed by long-range interactions between electrons. Perturbation theory in a large number of flavors is used in which the interactions are described within a random phase approximation, taking account of dynamical screening effect. Crucially, the dynamically screened interaction retains some long-range character, resulting in log2 renormalization of key quantities. We carry out the perturbative renormalization group calculations to one loop order and find that BLG behaves to leading order as a marginal Fermi liquid. Interactions produce a log squared renormalization of the quasiparticle residue and the interaction vertex function while all other quantities renormalize only logarithmically. We solve the RG flow equations for the Green’s function with logarithmic accuracy and find that the quasiparticle residue flows to zero under RG. At the same time, the gauge-invariant quantities, such as the compressibility, remain finite to log2 order, with subleading logarithmic corrections. The key experimental signature of this marginal Fermi liquid behavior is a strong suppression of the tunneling density of states, which manifests itself as a zero bias anomaly in tunneling experiments in a regime where the compressibility is essentially unchanged from the noninteracting value.
Date issued
2010-09Department
Massachusetts Institute of Technology. Department of PhysicsJournal
Physical Review B
Publisher
American Physical Society
Citation
Nandkishore, Rahul and Leonid Levitov. "Electron interactions in bilayer graphene: Marginal Fermi liquid and zero-bias anomaly." Physical Review B 82.11 (2010) : 115431. © 2010 The American Physical Society
Version: Final published version
ISSN
1098-0121
1550-235X