Dynamic excitations of nanomagnet magnetization driven by spin-polarized current

A current of spin-polarized electrons injected into a metallic nanomagnet exerts torque on the magnetization and may excite magnetization autooscillations. The aim of present work is to study spectral and transient properties of such excitations. We study current-driven excitations in a permalloy (Py) elliptical nanomagnet. We also make time-resolved measurements of the ac voltage generated by the current-driven excitations using a storage oscilloscope.