Regensburg 2016 – scientific programme
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MA: Fachverband Magnetismus
MA 39: Magnetic Particles
MA 39.6: Talk
Thursday, March 10, 2016, 10:45–11:00, H31
Theory of nano-spintronic logic functionalities on a Ni4 cluster — •Wolfgang Hübner, Georgios Lefkidis, and Debapriya Chaudhuri — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67653 Kaiserslautern, Germany
Starting from high level, ab initio calculations, we present several new all-spin-based nano-logic functionalities, which require a minimum of four active magnetic centers. The underlying mechanisms for all operations are coherent Λ processes, driven by suitably tailored laser pulses.
Our calculations indicate, that in the geometrically optimized Ni4 cluster the spin density exhibits a high degree of localization. In addition to ultrafast (90 fs) optically triggered local spin flips and spin transfers, which require only one or two atomic magnetic centers, we demonstrate the following operations with sufficiently high fidelity: spin bifurcation and its reverse (spin association/ merging), as well as the which path interference. We construct two nano-logic elements: a 4-bit cyclic SHIFT register [1] and a pure-spin OR gate [2]. The former depends on the appropriate combinations of the spin transfer scenarios whereas the latter depends on the spin association. The which path interference employs the phase of the final spin state of a two-step spin transfer process which depends on the exact path traveled by the spin.
The scenarios provide the necessary basic functionalities for nano-logic applications.
[1] G. D. Mahan, Phys. Rev. Lett. 102, 016801 (2009).
[2] D. Chaudhuri, University of Kaiserslautern, Ph.D. Thesis (2016).