Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 34: Spin controlled transport II

HL 34.2: Vortrag

Mittwoch, 25. März 2009, 14:15–14:30, BEY 118

Ballistic Intrinsic Spin-Hall Effect in HgTe Nanostructures — •Christoph Brüne¹, Andreas Roth¹, Elena G. Novik¹, Markus König¹, Ewelina Hankiewicz², Hartmut Buhmann¹, and Laurens W. Molenkamp¹ — ¹Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg, Germany — ²Institut für Theoretische Physik und Astrophysik, Universität Würzburg, 97074 Würzburg, Germany

Due to their unique band structure and the high spin orbit coupling strength, HgTe/HgCdTe quantum wells provide a good system for the observation of spin dependend transport phenomena. In this work we used nano-scale H-shaped structures built on HgTe/HgCdTe quantum wells to detect the intrinsic spin-Hall effect (ISHE) in a non-local electrical measurement. The strength of the spin orbit coupling was controlled by a top gate, which also made a transition from n- to p-conductance possible. The observed non-local resistance signal in the p-regime is in the order of kΩ. In contrast in the n-regime the signal is at least an order of magnitude lower. These observations are in agreement with bandstructure considerations and are confirmed by detailed Landauer-Büttiker-Keldysh formalism calculations.