Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 4: Spintronics: Nanostructures and Optics
HL 4.2: Vortrag
Montag, 7. März 2016, 09:45–10:00, H13
Spin Dynamics in Single Wurtzite GaAs Nanowires — •Florian Dirnberger, Stephan Furthmeier, Andreas Bayer, Joachim Hubmann, Benedikt Bauer, Moritz Forsch, Josef Zweck, Elisabeth Reiger, Christian Schüller, Tobias Korn, and Dominique Bougeard — Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg, Deutschland
Spin orbit coupling (SOC) in semiconductor nanowires (NWs) is currently attracting great interest regarding the application of spintronic and spin-orbitronic concepts. The action of this relativistic effect can be experimentally captured through its influence on the spin dynamics in the material. In contrast to electrical spin injection by means of ferromagnetic contacts, optical orientation with circularly polarized light provides a contact-free, non-invasive method to investigate the spin dynamics in semiconductors.
In this contribution, we demonstrate for the first time efficient optical spin orientation in single free-standing wurtzite (WZ) GaAs/AlGaAs core-shell nanowires. Our WZ nanowires are stacking-fault-free over lengths of several µm. We investigated the intrinsic spin dynamics in time-resolved micro-photoluminescence measurements on single NWs and observed long spin lifetimes up to τs = 1.5 ns. The spin dynamics further reveal an anisotropic SOC for the studied NWs, which is counterintuitive compared to bulk WZ semiconductors. We present a model of the observed electron spin dynamics which highlights the major role of the interface SOC in these nanowires.