Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 22: Graphene 2 (Joint Session with TT)

HL 22.4: Vortrag

Dienstag, 23. März 2010, 10:15–10:30, H21

Direct measurement of the electron mean free path in few layer graphene samples — •Srujana Dusari, Jose Barzola-Quiquia, and Pablo Esquinazi — Division of Superconductivity and magnetism, Institute for Experimental Physics II, University of Leipzig, 04103 Leipzig, Germany

The large coherence length of the electrons in graphite is expected to lead to a long electronic mean free path and to a large spin-diffusion length even at room temperature [1]. The aim of this work is the direct measurement of the electron mean free path, Fermi wavelength and mobility and their temperature dependence in multigraphene samples, i.e. micrometer large few layer graphene (FLG) samples with thickness below 100 nm. This is possible by studying the electronic transport through constrictions using specific design and nanostructuring of the sample. By measuring the resistance before and after making constrictions of different size it is possible to obtain the necessary parameters [1]. We developed a new method to avoid Ga+ ion contamination while making the constriction on the samples. First results on the temperature dependence of the mean free path in FLG samples obtained without free parameters will be presented.

[1]. N García, P. Esquinazi, J. Barzola-Quiquia, B. Ming, and D. Spoddig, Phys. Rev. B 78, 035413 (2008).