Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 111: Graphene: Bi- and multi-layers (with MA/O/TT)

HL 111.6: Talk

Friday, April 4, 2014, 10:45–11:00, POT 081

Conductivity of two-dimensional charge carriers with non-parabolic dispersion — Bretislav Sopik¹, Janik Kailasvuori^2,3, and •Maxim Trushin⁴ — ¹Central European Institute of Technology, Masaryk University, Kamenice 735, 62500 Brno, Czech Republic — ²International Institute of Physics, Universidade Federal do Rio Grande do Norte, 59078-400 Natal-RN, Brazil — ³Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden, Germany — ⁴University of Konstanz, Fachbereich Physik, M703 D-78457 Konstanz

We investigate the conductivity of two-dimensional charge carriers with the non-parabolic dispersion k^N with N being an arbitrary natural number assuming the delta-shaped scattering potential as a major source of disorder. We employ the exact solution of the Lippmann-Schwinger equation to derive an analytical Boltzmann conductivity formula valid for an arbitrary scattering potential strength. We proceed further with a numerical study based on the finite size Kubo formula which assesses the applicability range of our analytical model. We find that for any N>1, the conductivity demonstrates a linear dependence on the carrier concentration in the limit of a strong scattering potential strength. This finding agrees with the conductivity measurements performed recently on chirally stacked multilayer graphene [1] where the lowest two bands are non-parabolic and the adsorbed hydrocarbons might act as strong short-range scatterers.

[1] L. Zhang, Y. Zhang, J. Camacho, M. Khodas I. Zaliznyak, Nature Physics 7, 953-957 (2011).