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MA: Fachverband Magnetismus
MA 40: Focus: Terahertz radiation and magnetism
MA 40.3: Hauptvortrag
Donnerstag, 10. März 2016, 10:45–11:15, H32
THz Spintronics: Magnetotransport and Magnonics — •Zuanming Jin1,2, Mathias Kläui3, Tobias Kampfrath4, Guohong Ma2, Mischa Bonn1, and Dmitry Turchinovich1 — 1Max Planck Institute for Polymer Research,Mainz,Germany — 2Department of Physics,Shanghai University,Shanghai,China — 3Institut für Physik, Johannes Gutenberg-Universität Mainz,Mainz,Germany — 4Fritz Haber Institute of the Max Planck Society,Berlin,Germany
Spin-dependent conduction in metals underlies all modern magnetic memory technologies, such as giant magnetoresistance (GMR). According to the fundamental Mott model, the charge current in ferromagnetic transition metals is carried by non-mixing populations of sp-band Fermi-level majority- and minority-spin electrons, experiencing spin-dependent momentum scattering with localized electrons originating from the spin-split d-band. The direct observation of magneto transport under such fundamental conditions, however, requires the conductivity measurements on the ultrafast, sub-100 fs timescale, at which the electron momentum scattering occurs. Here, using ultrafast terahertz spectroscopy on a GMR spin-valve, we directly observe the magneto transport in a metallic system under the fundamental conditions of Mott model. As a result, we are able to directly determine the fundamental parameters of magneto-transport - spin-dependent densities and momentum scattering times of conduction electrons in a ferromagnetic metal. Further, we will discuss the direct excitation, observation, and coherent control of THz-frequency magnons in rare-earth orthoferrites.