Dresden 2011 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 15: ISPS Intersectional Poster Session

DY 15.28: Poster

Tuesday, March 15, 2011, 18:00–20:00, P1

Thermopower in Bilayer Graphene — •Aleksander Hinz — School of Engineering and Science, Jacobs University Bremen, Bremen 28759, Germany

In this work we present our theoretical approach to investigate Thermopower in Bilayer Graphene. Inspired by Seoung-Geol Nam's experimental work in late 2009 [1] as a member of the group of Hu-Jong Lee at Postech University, S.Korea, we seek to provide a theorecical underpinning for the observed phenomena concerning Bilayer Graphene.

Since our theoretical framework for Monolayer Graphene, which is based upon the description of conductivity including diffusion on impurities by using the linear response theory within the diagrammatic description, is in good accordance with experimental data only for Monolayer and not for Bilayer Graphene, we devise a modification of this framework, taking into account additional physical effects beyond impurity diffusion.

The effect investigated in this work is the electron-phonon interaction, that leads to a Phonondrag component in Thermopower at low temperature, while at higher temperature this effect is suppressed by phonon-phonon interaction. In contrast to the diffusive part we here apply the Boltzmann equation description as well as the balance-equation-based examination, which appreas to be sufficient for our case. This serves as an approach to explain the observed disagreement between experimental results and corresponding calculations using the classical Mott formula in Seoung-Geol Nam's work [1].

[1] S. Nam, D. Ki, and H. Lee, arXiv:1005.4739