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DY: Fachverband Dynamik und Statistische Physik
DY 9: Graphene II (organised by TT)
DY 9.14: Vortrag
Montag, 14. März 2011, 17:45–18:00, HSZ 304
Transport in Rough Quasi-One-Dimensional Systems — •Otto Dietz1, Ulrich Kuhl1,2, Hans-Jürgen Stöckmann1, Felix M Izrailev3, and Nykolay M Makarov3 — 1Universität Marburg, Germany — 2Université de Nice, France — 3Universidad de Puebla, Mexico
Scattering at rough disordered boundaries strongly influence the conductance of nanowires. For rough silicon nanowires a much higher ratio of electric conductivity to thermal conductivity has been reported than expected from the Wiedemann-Franz law [1]. These findings have not been explained yet.
In the case of bulk disorder it is well known that correlations can drastically change conductance properties [2]. Similar effects have been predicted for rough nanowires [3] but drew little attention before their applicability to conductivity in silicon nanowires became evident.
We present a first experimental test of this theory in microwave waveguides with rough walls. Because of the strict analogy between the 2d Schrödinger equation and the Helmholtz equation, the results can be directly applied to electron transport in nano structures. Microwave techniques can be helpful in this respect, since in contrast to real nanowires the surface roughness is both known and controllable. We could confirm that certain rough boundaries can block or enhance wave transport in given frequency windows. \newline [1] A. I. Hochbaum, et. al., Nature 451, 163 (2008). \newline [2] U. Kuhl, et.al., Appl. Phys. Lett. 77, 633 (2000). \newline [3] M. Rendón, et.al., Phys. Rev. B 75, 205404 (2007).