Precessional modes due to spin-transfer in spin-valve nanopillars

Thermally Assisted Current-Driven Dynamics in Asymmetric Spin Valves

Current-induced steady precessional modes in standard spin valves are usually excited as an interplay of spin-transfer torque, Gilbert damping, and external magnetic field. We propose an asymmetric spin valve, in which the spin current can excite stationary precessional modes also at zero external magnetic field. We also show that finite temperature can induce transitions between different dyna...

Spin-transfer switching in spin valve nanopillars RESEARCH SEMESTER REPORT

Spin-transfer assisted thermally activated switching distributions in perpendicularly magnetized spin valve nanopillars

We present switching field distributions of spin-transfer assisted magnetization reversal in perpendicularly magnetized Co/Ni multilayer spin-valve nanopillars at room temperature. Switching field measurements of the Co/Ni free layer of spin-valve nanopillars with a 50 nm× 300 nm ellipse cross section were conducted as a function of current. The validity of a model that assumes a spin-current d...

Spin Transfer in Magnetic Nanopillars

This thesis describes experimental studies of spin-transfer induced magnetization switching and dynamics in bilayer magnetic nanopillars. Known as the spin transfer effect, a spin-polarized current can transfer its angular momentum to a magnetic layer, resulting in its reversal as well as microwave dynamics. It has become a major focus in both physics and technology. Our nanostructured spin val...

Time-domain studies of very-large-angle magnetization dynamics excited by spin transfer torques

We describe time-domain measurements which provide information about the large-angle nonlinear dynamics of nanomagnets excited by spin-transfer torque from a spin-polarized current. Sampling-oscilloscope measurements, which average over thousands of experimental time traces, show that the mean reversal time for spin-transfer-driven magnetic switching has a steplike dependence on magnetic field,...