Micromagnetic Investigation of Magnetic Dynamics Induced by Spin - Transfer - Torque

As predicted by Slonczewski [1] and Berger [2], the magnetization switching [3] and the microwave excitation [4] in a nanomagnet by a spin-polarized current has been experimentally demonstrated. It is ascribed to spin-angular-momentum-transfer of incoming electrons to local magnetizations, i.e. spin-transfer-torque. The spintransfer-torque is attracting a considerable interest because of its applicability to various spintronic devices. A micromagnetic study using numerical calculations is essential to understand this new physics because the dynamic magnetization state is not described within the framework of single domain in some cases.