Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 20: Spin controlled transport II

HL 20.4: Talk

Tuesday, March 28, 2006, 16:00–16:15, BEY 118

Conductance Quantization in Quantum Point Contacts with Spin-Orbit Interaction — •Sebastian von Oehsen, Guido Meier, Toru Matsuyama, and Ulrich Merkt — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Germany

InAs has a strong and tunable spin-orbit interaction [1] and is thus an interesting material for spintronic devices. We present measurements on quantum point-contacts on InAs/InGaAs heterostructures.

Hallbars are predefined on the samples by wet etching. To achieve lateral electrostatic confinement we use either split gates on a SiO₂ layer or side gates. With the latter technique peripheral charging effects can be avoided because of the absence of an isolator. The measurements are performed at 250 mK and in magnetic fields up to 5 Tesla. Quantization steps in the conductance are measured. The transition from electrostatic to magnetic confinement is examined and compared with recent theoretical results [2].

[1] Ch. Schierholz, T. Matsuyama, U. Merkt, and G. Meier. Phys. Rev. B 70, 233311 (2004)

[2] S. Debald and B. Kramer, Phys. Rev. B 71, 115322 (2005)