Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 66: Transport Properties III (Experiments)
HL 66.3: Vortrag
Mittwoch, 28. März 2012, 18:45–19:00, ER 164
Ballistic and thermoelectric contributions to transverse rectification in density-modulated 2D-systems — •Arkadius Ganczarczyk1, Andy Quindeau1, Martin Geller1, Axel Lorke1, Dirk Reuter2, and Andreas D. Wieck2 — 1Experimental Physics and CeNIDE, Universität Duisburg-Essen — 2Chair of Applied Solid State Physics, Ruhr-Universität Bochum
We investigate tunable transverse rectification in a density-modulated two-dimensinal electron gas (2DEG) from T = 1.8 K to 300 K. The 2DEG is patterned into a hall bar geometry. Using gate electrodes we induce two stripes of different charge carrier densities along the channel. The resulting density gradient perpendicular to the channel induces a transverse voltage, which - due to the symmetry of the device - does not change polarity when the current direction is reversed [1, 2].
To acquire a deeper insight into the physics behind this rectification effect, we investigate its dependence on modulation strength, temperature and the width of the stripes. The results are discussed using a billiard model, which describes the propagation of ballistic electrons in density-modulated 2D-systems. Also possible thermoelectric effects in the structure are considered. In order to calculate the expected thermoelectric voltage in such a system, the electron temperatures in the heated electron gas are determined experimentally. Both models are compared in order to obtain a deeper insight into this novel rectification effect.
A. Ganczarczyk et al., preprint:arXiv:0804.0689v3 (2009).
A. Ganczarczyk et al., AIP Conf. Proc. 1199, 143 (2009).