title: Uniaxial spin-transfer torque in an exchange-biased spin valve.
abstract: We study the effects of uniaxial spin-transfer torque (USTT) on the ferromagnetic (F) as well as antiferromagnetic (AF) layers in an exchange-biased (EB) spin valve. By analytically treating the free-energy functional of the F/AF bilayer and numerically solving the Landau-Lifshitz-Gilbert equation for magnetic moments, we can reproduce and explain two existing experimental facts relevant to USTT: one is that the EB field can be reversed by both positive and negative pulsed currents, and the other is that the critical current to excite the F moments is greatly increased in the presence of an AF layer and independent of external fields. We also derive the angular dependence of the critical currents to excite AF and F moments, which suggests a possible way to quantitatively determine USTT in experiments.
authors: National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, People's Republic of China.
authors: Jian-qing
authors: JQ
authors: Xu
authors: Guojun
authors: G
authors: Jin