Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 78: Transport: Graphene 1 (jointly with TT, MA, DY, DS, O)

HL 78.6: Vortrag

Donnerstag, 29. März 2012, 10:45–11:00, BH 334

Coulomb drag in graphene via kinetic equation approach — •Michael Schuett¹, Pavel M. Ostrovsky^1,2, Igor V. Gornyi^1,3, Mikhail Titov⁴, Boris N. Narozhny⁵, and Alexander D. Mirlin^1,5,6 — ¹Institut für Nanotechnologie, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany — ²L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow, Russia — ³A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia. — ⁴School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK — ⁵Institut für Theorie der kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany — ⁶Petersburg Nuclear Physics Institute, 188350 St. Petersburg, Russia.

We calculate the Coulomb drag resistivity at finite temperature for two graphene monolayers within the kinetic equation approach. The emphasis is put on the case of fast electron-electron collisions compared to disorder induced scattering. We obtain the asymptotic behavior of the Coulomb drag resistivity ρ_D both for small chemical potentials (µ₁,µ₂) in the two layers as well as chemical potentials larger than temperature. When only one layer is at the Dirac point the Coulomb drag resistivity is zero. However when approaching the Dirac point of both layers simultaneously, the Coulomb drag resistivity does not vanish as long as µ₁∝µ₂→ 0. For any finite disorder strength or alternating current Coulomb drag resistivity obeys again ρ_D(µ₁=0,µ₂=0)=0, as expected from the particle hole symmetry argument. When both layers have large chemical potentials we recover the Fermi liquid behavior.