Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene

Details Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene

2009-06-30

arxiv.org/abs/0906.5534v1

Phys. Rev. B 80 (2009) 165430

Physics

Condensed Matter

Materials Science

7 pages, 7 figures

Scientific paper

10.1103/PhysRevB.80.165430

We study how the electronic structure of the bilayer graphene (BLG) is changed by electric field and strain from {\it ab initio} density-functional calculations using the LMTO and the LAPW methods. Both hexagonal and Bernal stacked structures are considered. The BLG is a zero-gap semiconductor like the isolated layer of graphene. We find that while strain alone does not produce a gap in the BLG, an electric field does so in the Bernal structure but not in the hexagonal structure. The topology of the bands leads to Dirac circles with linear dispersion in the case of the hexagonally stacked BLG due to the interpenetration of the Dirac cones, while for the Bernal stacking, the dispersion is quadratic. The size of the Dirac circle increases with the applied electric field, leading to an interesting way of controlling the Fermi surface. The external electric field is screened due to polarization charges between the layers, leading to a reduced size of the band gap and the Dirac circle. The screening is substantial in both cases and diverges for the Bernal structure for small fields as has been noted by earlier authors. As a biproduct of this work, we present the tight-binding parameters for the free-standing single layer graphene as obtained by fitting to the density-functional bands, both with and without the slope constraint for the Dirac cone.

Affiliated with

Also associated with

No associations

Rating

Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Strain and Electric Field Modulation of the Electronic Structure of Bilayer Graphene will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-441030