Electron transport in magnetic nanostructures.doc

此文档收集于网络，如有侵权，请联系网站删除YOUNG RESEARCHERS INTRODUCTIONGen TATARAAssociate Professor, Graduate School of Science, Tokyo Metropolitan University Electron transport in magnetic nanostructures(Issued in Japanese: September 29, 2004)My main area of research is the theoretical study of magnetoresistance and current-driven magnetization reversal. The integration of magnetic and electric properties is an important research area because current technology involves magnetic devices which are based on the magnetoresistive effect arising from modification of the electron transport by the magnetic configuration. Moreover, the manipulation of the state of magnetization assisted by an electric current is promising technology for the next generation magnetic memories, in which the information is written by an electric current.Although there have been theoretical studies on the current-driven magnetization dynamics, they are phenomenological and thus have had limited applicability. Very recently, I formulated a self-contained microscopic theory on the domain wall dynamics induced by an electric current. In this theory, the electric current required to drive a domain wall and the dependence of the wall velocity on the applied current were evaluated. The results will be quite useful in designing new magnetic devices, in which the magnetic information is efficiently written by a current.Gen TATARAAssociate Professor, Graduate School of Science, Tokyo Metropolitan University 1987BS in physics, Department of Physics, Faculty of Science, The University of Tokyo.1989MS in physics, Department of Physics, Faculty of Science, The University of Tokyo.1992Doctor of Science, Department of Physics, Faculty of Science, The University of Tokyo.19921993Postdoctoral fellow at the Department of Physics, Faculty of Science, The University of Tokyo19941996Postdoctoral fellow at the Institute of Physical and Chemical Research (RIKEN)19962005Assistant professor, Graduate School of Science, Osaka University19981999Alexander von Humboldt fellow (Max-Planck-Institute for Microstructurphysics)2001visiting professor, Joseph Fourier University, Grenoble (The French National Center for Scientific Research (CNRS)2005presentAssociate Professor, Graduate School of Science, Tokyo Metropolitan UniversityE-mail: tatara(AT)phys.metro-u.ac.jp Click the email address to contact.homepage Fig. 1 Magnetic recording by use of a domain wall motion driven by electric-current. The reflection of the electron and spin flip during the transmission results in domain wall motion by transferring momentum and spin angular momentum, respectively.Fig. 2 Domain wall motion by spin torque from the spin-polarized current, js. The torque due to js is partially absorbed by the magnetization tilt from the easy plane, but if js is sufficiently large, the tilt cannot support all the torque and the wall starts to move.a movie file describing the motion(MPEG3 1.2MB) Relevant papers1. Tatara, G. & Kohno, H.Theory of Current-Driven Domain Wall Motion: Spin Transfer versus Momentum TransferPhys. Rev. Lett. 92, 086601-(1-4) (2004). 2. Shibata, J., Tatara, G. & Kohno, H.Effect of Spin Current on Uniform Ferromagnetism: Domain NucleationPhys. Rev. Lett. 94, 076601-1-076601-4 (2005). 3. Saitoh, E., Miyajima, H., Yamaoka, T. & Tatara, G.Current-induced resonance and mass determination of a single magnetic domain wallNature 432, 203-206 (2004). 4. Tatara, G. & Kohno, H.Permanent current from noncommutative spin algebraPhys. Rev. B 67, 113316-(1-3) (2003). 5. Tatara, G.& Garcia,N.Quantum toys for quantum computing: persistent currents controled by the spin Josephson effectPhys. Rev. Lett. 91, 076806