Dresden 2006 – wissenschaftliches Programm

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SYNW: Nano Wires

SYNW 2: Symposium: Nano-Wires II

SYNW 2.1: Hauptvortrag

Mittwoch, 29. März 2006, 16:00–16:30, HSZ 04

Quantum devices based on heterostructure semiconductor nanowires — •Claes Thelander — Solid State Physics, Lund University, 221 00 Lund, Sweden

Epitaxial growth of heterostructure InAs/InP semiconductor nanowires will be described. Fabrication of Ohmic contacts to such nanowires allows investigation of their transport characteristics. We observe that thin InAs nanowires experience strong radial quantum confinement and are depleted of charge carriers, whereas thicker wires are almost metal-like. A few quantum-based devices realized in the InAs/InP heterostructure system will be presented. Growth of a short (10 nm) InAs dot section between two InP tunnel barriers results in very strong quantum confinement along the axial direction. Filling such a dot with ~20 electrons only involves the ground state in the axial direction, and clear shell filling effects are observed due to spin and orbital degeneracies in the radial directions. We also investigate electron transport in multiple tunnel junction devices. It is demonstrated that electrons can be stored in meta-stable states in a tunnel junction-based nanowire memory containing up to 10 InP barriers. Memories based on electron tunneling are predicted to have considerable faster write speeds than corresponding devices relying on thermionic emission over a barrier.