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HL: Halbleiterphysik

HL 10: Quantenpunkte und -dr
ähte: Transporteigensch. II

HL 10.2: Talk

Monday, March 11, 2002, 15:45–16:00, H17

Magnetic-field effects on the Transport Properties of Rough Wires — •Antonio Garcia-Martin¹, Michele Governale², and Peter Wölfle¹ — ¹Institut für Theorie der Kondensierten Materie, Universität Karlsruhe, 76128 Karlsruhe — ²Institut für Theoretische Festkörperphysik, Universität Karlsruhe, 76128 Karlsruhe

Progress in miniaturization techniques leads to very clean wires with a rather small number of propagating channels. In this situation surface disorder becomes more and more relevant and easily outplays bulk disorder. We present a detailed numerical analysis of the effect of a magnetic field on the transport properties of a few-channel wire with a single disordered surface. We find a large increase not only of the localization length but also of the mean free path for increasing magnetic field. We also analyze the conductance distribution at the metal-insulator transition, finding a very good agreement with Random Matrix Theory for two fluctuating channels within the Circular Orthogonal(Unitary) Ensemble in absence(presence) of the magnetic field.