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HL: Halbleiterphysik

HL 12: Quantenpunkte und -dr
ähte: Transporteigenschaften II

HL 12.1: Vortrag

Montag, 24. März 2003, 15:15–15:30, POT/81

Weak localization in laterally-coupled quantum wires — •O. Bierwagen¹, C. Walther², K.-J. Friedland³, and W. T. Masselink¹ — ¹Institut für Physik, Humboldt-Universität zu Berlin, Invalidenstrasse 110, 10115 Berlin — ²Infineon AG, Dresden — ³Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin

The magnetotransport properties of laterally-coupled self-organized InAs quantum wires are investigated, focusing on the contributions to conductivity resulting from weak localization.

Modulation-doped InAs wire-like structures with typical dimensions of 200 nm by 25 nm by 2 nm were grown on InP(001) buffer layers using gas-source molecular-beam epitaxy through Stranski-Krastanov self-organization. Because of the high density and correspondingly large coupling of these quantum wires, lateral magnetotransport both parallel and perdicular to the length of the wires could be measured.

We demonstrate that the weak-localization correction to conductivity shows a directional anisotropy equal to the anisotropy of the total conductivity and can be fit using a model for a two-dimensional system with asymmetric mobility. This result suggests that even for a conductivity anisotropy ratio as high as 14, the coupling between the quantum wires plays a more important role than the quasi-one-dimensional nature of the electron transport in describing the quantum mechanical contributions due to weak localization.