Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 102: Quantum dots and wires: Transport
HL 102.5: Vortrag
Freitag, 15. März 2013, 12:15–12:30, H13
Investigation of Spin-Orbit Coupling in Differently Doped InAs Nanowires — •Sebastian Heedt1, Thomas Gerster1, Isabel Wehrmann1,2, Kamil Sladek1, Hilde Hardtdegen1, Detlev Grützmacher1, and Thomas Schäpers1,3 — 1Peter Grünberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425 Jülich, Germany — 2OSRAM Opto Semiconductors GmbH, 93055 Regensburg, Germany — 3II. Physikalisches Institut, RWTH Aachen University, 52056 Aachen, Germany
Low-temperature quantum transport is presented for top-gated InAs nanowires prepared by selective area metalorganic vapor phase epitaxy. The carrier concentration and the band profile can be controlled by means of doping or the application of a gate voltage. Phase-coherent transport is investigated for temperatures down to 30 mK and magnetic fields up to 10 T. Utilizing an analytical model for the low-field quantum conductivity correction, we are able to extract the phase coherence length lφ and the spin relaxation length lso. The model applies for diffusive wires with diameters falling short of lφ. It accounts for spin relaxation under linear Rashba and linear and cubic Dresselhaus spin-orbit coupling. To investigate these effects, superimposed universal conductance fluctuations have to be eliminated by averaging magnetic field dependent measurements across a wide gate voltage range. Thus, individual nanowires with different doping concentrations are investigated to gain information on how the doping of the highly spin-orbit coupled InAs nanowires impacts the spin-lifetime.