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HL: Fachverband Halbleiterphysik
HL 28: Transport properties
HL 28.6: Vortrag
Dienstag, 26. Februar 2008, 10:45–11:00, ER 164
Flexural phonons in free-standing graphene — •Eros Mariani and Felix von Oppen — Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)
Rotation and reflection symmetries impose that out-of-plane (flexural) phonons of free-standing graphene membranes have a quadratic dispersion at long wavelength and can be excited by charge carriers in pairs only. As a result, we find that flexural phonons dominate the phonon contribution to the resistivity ρ below a crossover temperature Tx where we obtain an anomalous temperature dependence ρ∝ T5/2lnT. The logarithmic factor arises from renormalizations of the flexural phonon dispersion due to coupling between bending and stretching degrees of freedom of the membrane.