Screening, Kohn Anomaly, Friedel Oscillation, and RKKY Interaction in Bilayer Graphene

E. H. Hwang, S. Das Sarma
2008 Physical Review Letters  
We calculate the screening function in bilayer graphene (BLG) both in the intrinsic (undoped) and the extrinsic (doped) regime within random phase approximation, comparing our results with the corresponding single layer graphene (SLG) and the regular two dimensional electron gas (2DEG). We find that the Kohn anomaly is strongly enhanced in BLG. We also discuss the Friedel oscillation and the RKKY interaction, which are associated with the non-analytic behavior of the screening function at
more » ... g function at q=2k_F. We find that the Kohn anomaly, the Friedel oscillation, and the RKKY interaction are all qualitatively different in the BLG compared with the SLG and the 2DEG.
doi:10.1103/physrevlett.101.156802 pmid:18999623 fatcat:cqzebyj4wrgmppze2jvjudnnmm