Regensburg 2002 – scientific programme

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HL: Halbleiterphysik

HL 29: Spinabh
ängiger Transport

HL 29.3: Talk

Wednesday, March 13, 2002, 16:00–16:15, H13

Filtering Spin without Zeeman or Exchange fields — •Michele Governale, Daniel Boese, Ulrich Zülicke, and Christian Schroll — Institut für Theoretische Festkörperphysik, UniversitätKarlsruhe, D-76128 Karlsruhe, Germany

The operation of most spintronic devices requires the ability to inject spin-polarized electrons in nonmagnetic semiconductors. To this end, the use of Zeeman splitting is impractical, as it requires strong on-chip magnetic fields. An alternative, and more promising approach, exploits the exchange field in magnetic materials in hybrid structures. We take a different route, making use of intrinsic spin-dependent effects. We propose a spin-filtering device based on the interplay of the Rashba spin-orbit coupling and wave-number selectivity due to momentum-resolved tunneling in parallel quantum wires. Spin polarized currents are created by applying voltages or small orbital magnetic fields. Moreover, the proposed setup offers the possibility of direct spectroscopic observation of Rashba-split bands in semiconductor quantum wires.