193rd Special MMU seminar

Current-induced magnetic domain wall motion and its application

Prof. Teruo ONO Institute for Chemical Research, Univ. of Kyoto, Uji, 611-0011, Japan

Date: March 6th (Thu), 2014
Time: 13:30 - 14:30
Place: 8F medium seminar room, Sengen

When a magnetic DW is driven by electric current via adiabatic spin torque, the theory predicts a finite threshold current even for a perfect wire without any extrinsic pinning [1]. We have shown that this intrinsic pinning determines the threshold current, and thus that the adiabatic spin torque dominates the DW motion resulting in DW motion along electron flow direction, in a perpendicularly magnetized Co/Ni system sandwiched by a symmetric capping and seed layers [2-8].
On the other hand, current-induced DW motion against electron flow direction has been observed in ultrathin magnetic films in which the structural inversion symmetry (SIA) was broken [9, 10]. Recently, this DW motion against electron flow direction has been explained by the combination of a chiral DW and spin Hall torque [11, 12].
In this presentation, I will show the systematic investigation by changing thickness of Co/Ni layer and discuss the contribution of adiabatic spin transfer torque, and spin Hall torque in the current-induced DW motion. I will also discuss possible applications using the current-induced DW motion.
This work was partly supported by a Grant-in-Aid for Scientific Research (S) and "Funding program for world-leading innovative R & D on science and technology" (FIRST program) from the Japan Society for the Promotion of Science.

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