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O: Fachverband Oberflächenphysik
O 11: Graphene: Spin-orbit interaction (jointly with DS, HL, MA, and TT)
O 11.5: Vortrag
Montag, 11. März 2013, 12:30–12:45, H17
Tunneling-induced Spin Anisotropy Barrier in Quantum Dot Spin-Valves — •Michael Hell1,2, Maciej Misiorny1,2, and Maarten Wegewijs1,2,3 — 1Peter Grünberg Institut, Forschungszentrum Jülich, 52425 Jülich — 2JARA - Fundamentals of Future Information Technology — 3Institut für die Theorie der Statistischen Physik, RWTH Aachen, 52056 Aachen
Spintronics employs the two fundamental properties of a each electron: its charge and its spin-dipole moment. However, recent studies indicate that the interplay of these two degrees of freedom does not exhaust the potential of spintronics when approaching the nano-scale: spin correlations between electrons, partly characterized by the spin-anisotropy, provide an independent resource of spin information, which is stored even in a simple ferromagnet and couples to the spin-dipole moment in quantum dots. The interest in spin anisotropy also emerges from the research on single-molecule magnets (SMMs) and magnetic adatoms, in which the transport is controlled by a large spin anisotropy barrier intrinsically generated by strong spin-orbit coupling. In this talk we show that such a spin-anisotropy barrier can be externally induced by the transport of spin-correlations from ferromagnets into a a spin-isotropic interacting quantum dot with large spin S>1/2 and negligible spin-orbit interaction. This proximity-induced spin-anisotropy has the hallmarks of a spintronic exchange-field of a quadrupolar nature, a generalization of the well-established dipolar exchange field. The barrier increases with the tunnel coupling, achieving values comparable to that of SMMs, but with the flexibility of electric and magnetic tuneability.