Spintronic oscillators can be realized by considering two ferromagnets separated by a normal metal or a ultrathin (<1.2nm) insulator. One of the ferromagnets acts as polarizer while the other, namely the free layer, is designed in order that a large enough spin-polarized current can modify its magnetic state. In particular, if the negative damping exactly compensates the magnetic losses related to the Gilbert damping, a self-oscillation of the magnetization can be excited. In the literature, different kind of devices have been studied, spinvalves where the current is injected uniformly into the free layer, point contact geometries or nanowires where the current is injected locally into the free layer via a nanocontact. Here, we have investigated the dynamical properties of a nanowire spintronic oscillator (2500x100x6nm3) where the polarizer (100x100nm2) is in a vortex state localized in the center of the nanowire . An in-plane field of 50mT is applied to introduce a shift in the vortex core location. The initial configuration of the magnetization is uniform and aligned along the -x direction. Our results are based on the numerical solution of the Landau-Lifshitz-Gilbert- Slonczweski equation.
Nanowire spin-torque oscillator with non-uniform polarizer: a micromagnetic study - Presentazione poster - Conferenza internazionale
ZIVIERI, Roberto;
2014
Abstract
Spintronic oscillators can be realized by considering two ferromagnets separated by a normal metal or a ultrathin (<1.2nm) insulator. One of the ferromagnets acts as polarizer while the other, namely the free layer, is designed in order that a large enough spin-polarized current can modify its magnetic state. In particular, if the negative damping exactly compensates the magnetic losses related to the Gilbert damping, a self-oscillation of the magnetization can be excited. In the literature, different kind of devices have been studied, spinvalves where the current is injected uniformly into the free layer, point contact geometries or nanowires where the current is injected locally into the free layer via a nanocontact. Here, we have investigated the dynamical properties of a nanowire spintronic oscillator (2500x100x6nm3) where the polarizer (100x100nm2) is in a vortex state localized in the center of the nanowire . An in-plane field of 50mT is applied to introduce a shift in the vortex core location. The initial configuration of the magnetization is uniform and aligned along the -x direction. Our results are based on the numerical solution of the Landau-Lifshitz-Gilbert- Slonczweski equation.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
