Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2012-03-16
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
14 pages, 9 figures
Scientific paper
We estimate the strength of interaction-enhanced coherence between two graphene or topological insulator surface-state layers by solving imaginary-axis gap equations in the random phase approximation. Using a self-consistent treatment of dynamic screening of Coulomb interactions in the gapped phase, we show that the excitonic gap can reach values on the order of the Fermi energy at strong interactions. The gap is discontinuous as a function of interlayer separation and effective fine structure constant, revealing a first order phase transition between effectively incoherent and interlayer coherent phases. To achieve the regime of strong coherence the interlayer separation must be smaller than the Fermi wavelength, and the extrinsic screening of the medium embedding the Dirac layers must be negligible. In the case of a graphene double-layer we comment on the supportive role of the remote $\pi$-bands neglected in the two-band Dirac model.
MacDonald Allan. H.
Pesin D. A.
Sodemann Inti
No associations
LandOfFree
Interaction-Enhanced Coherence Between Two-Dimensional Dirac Layers 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 Interaction-Enhanced Coherence Between Two-Dimensional Dirac Layers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interaction-Enhanced Coherence Between Two-Dimensional Dirac Layers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-349022