Space charge and screening in bilayer graphene

Abstract

Undoped bilayer graphene is a two-dimensional semimetal with a low-energy excitation spectrum that is parabolic in the momentum. As a result, the screening of an arbitrary external charge $Ze$ is accompanied by a reconstruction of the ground state: valence band electrons (for $Z>0$) are promoted to form a space charge around the charge while the holes leave the physical picture. The outcome is flat neutral object resembling the regular atom except that for $Z\gg 1$ it is described by a strictly linear Thomas-Fermi theory. This theory also predicts that the bilayer's static dielectric constant is the same as that of a two-dimensional electron gas in the long-wavelength limit.

4+0 pages, 1 figure, minor changes, version to be published as a Letter in JPCM

References in corpus (9)

• The electronic properties of graphene
• The electronic properties of bilayer graphene
• Transport in Bilayer Graphene: Calculations within a self-consistent Born approximation
• Vacuum Polarization and Screening of Supercritical Impurities in Graphene
• Observing Atomic Collapse Resonances in Artificial Nuclei on Graphene
• Ballistic transmission through a graphene bilayer
• Screening, Kohn anomaly, Friedel oscillation, and RKKY interaction in bilayer graphene
• Nonlinear screening of charge impurities in graphene
• Screening of a hypercritical charge in graphene

Cited by in corpus (4)

• Heterobilayers of 2D materials as a platform for excitonic superfluidity
• Electron states in the field of charged impurities in two-dimensional Dirac systems
• Coulomb center instability in bilayer graphene
• Anomalous screening in two-dimensional materials with an extremum ring in the dispersion law