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HL: Fachverband Halbleiterphysik

HL 53: Transport properties

HL 53.5: Vortrag

Freitag, 27. März 2009, 11:15–11:30, POT 151

Nonlinear mesoscopic transport in asymmetric quantum wires — •Bettina Brandenstein-Köth, Lukas Worschech, Stefan Lang, Jan Heinrich, Sven Höfling, and Alfred Forchel — Technische Physik, Universität Würzburg, 97074 Würzburg

The nonlinear transport of asymmetric quantum wires has been studied under the influence of an external magnetic field. The investigated structures were based on a modulation doped GaAs/AlGaAs heterostructures with a two-dimensional electron gas approximately 80nm below the surface. The inplane asymmetry of the quantum wire was realized by two different side walls, one defined via an etched channel and the other by a metal-surface depletion gate. Magnetic fields were applied perpendicular to the sample surface. The conductance of the quantum wires was studied at a temperature of 4.2K. It was found that such asymmetric quantum wires show a pronounced magnetic-field asymmetry, defined as the change in the conductance induced by a change in the magnetic-field sign. The asymmetric conductance increases linearly with the bias voltage up to several hundred millivolts. We explain our findings by a recently proposed magnetic-field asymmetry of nonlinear mesoscopic transport.[1]

[1] D. Sánchez and M. Büttiker, Phys. Rev. Lett. 93, 106802 (2004); B. Spivak and A. Zyuzin, Phys. Rev. Lett. 93, 226801 (2004).