Observation of the intrinsic pinning of a magnetic domain wall in a ferromagnetic nanowire

• Published in: Nature materials Vol. 10; no. 3; pp. 194 - 197
• Main Authors: Ono, T, Koyama, T, Chiba, D, Ueda, K, Kondou, K, Tanigawa, H, Fukami, S, Suzuki, T, Ohshima, N, Ishiwata, N, Nakatani, Y, Kobayashi, K
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2011; Nature Publishing Group
• Subjects: 639/301/119/1001; 639/301/357/1016; 639/301/357/995; Adiabatic flow; Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Electric currents; Energy consumption; letter; Magnetic domains; Magnetism; Materials Science; Nanomaterials; Nanostructure; Nanotechnology; Nanowires; Optical and Electronic Materials; Pinning; Threshold currents; Torque; Walls
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat2961

The spin transfer torque is essential for electrical magnetization switching. When a magnetic domain wall is driven by an electric current through an adiabatic spin torque, the theory predicts a threshold current even for a perfect wire without any extrinsic pinning. The experimental confirmation of this 'intrinsic pinning', however, has long been missing. Here, we give evidence that this intrinsic pinning determines the threshold, and thus that the adiabatic spin torque dominates the domain wall motion in a perpendicularly magnetized Co/Ni nanowire. The intrinsic nature manifests itself both in the field-independent threshold current and in the presence of its minimum on tuning the wire width. The demonstrated domain wall motion purely due to the adiabatic spin torque will serve to achieve robust operation and low energy consumption in spintronic devices.