Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 21: Transport: Nanoelectronics II - Spintronics and Magnetotransport - Part 2
TT 21.10: Vortrag
Dienstag, 28. März 2006, 18:45–19:00, HSZ 105
Transport through anisotropic magnetic molecules — •Florian Elste1 and Carsten Timm2,1 — 1Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany — 2Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
We theoretically investigate inelastic transport through anisotropic magnetic molecules, weakly coupled to metallic leads. The differential conductance shows characteristic fine-structure splitting of the Coulomb blockade peaks originating from excitations involving nondegenerate spin multiplets. Magnetic anisotropy is found to be crucial for slow spin relaxation. In the presence of anisotropy we find giant spin amplification: If a bias voltage is applied to a molecule prepared in a spin-polarized state the spin accumulated in the leads can be made exponentially large. If the molecule is coupled to one ferromagnetic and one paramagnetic lead the molecular spin can be reversed by applying a bias voltage even in the absence of a magnetic field. For this case, the current-voltage characteristics reveal wide voltage ranges where the current is strongly suppressed due to selection rules for the spin. Spin blockade behavior is accompanied by negative differential conductance and super-Poissonian shot noise. Based on our findings, we propose schemes for reading and writing spin information in molecular memory devices.