We study theoretically current-induced dynamics of a transverse magnetic domain wall in bi-layer nanowires consisting of a ferromagnet on top of a nonmagnet having strong spin-orbit coupling. Domain wall dynamics is characterized by two threshold current densities, J_th^WB and J_th^REV, where J_th^WB is a threshold for the chirality switching of the domain wall and J_th^REV is another threshold for the reversed domain wall motion caused by spin Hall effect. The domain wall with a certain chirality may move opposite to the electron-flow direction with high speed in the current range J_th^REV < J < J_th^WB for the system designed to satisfy the conditions J_th^REV < J_th^WB and \alpha > \beta where \alpha is the Gilbert damping constant and \beta is the nonadiabaticity of spin torque. Micromagnetic simulations confirm the validity of analytical results.
Citation: Applied Physics Letters
Pub Type: Journals
spin-transfer torque, domain wall motion, spin Hall effect