Measurement of the spin-transfer-torque vector in magnetic tunnel junctions

Measurement of the spin-transfer-torque vector in magnetic tunnel junctions

The transfer of spin angular momentum from a spin-polarized current to a ferromagnet can generate sufficient torque to reorient the magnet’s moment. This torque could enable the development of efficient electrically actuated magnetic memories and nanoscale microwave oscillators. Yet difficulties in making quantitative measurements of the spin-torque vector have hampered understanding. Here we p...

Material for : “ Measurement of the Spin - Transfer - Torque Vector in Magnetic Tunnel Junctions ”

Time-resolved measurement of spin-transfer-driven ferromagnetic resonance and spin torque in magnetic tunnel junctions

The bias dependence of the torque that a spin-polarized current exerts on ferromagnetic elements is important for understanding fundamental spin physics in magnetic devices and for applications. Several experimental techniques have been introduced in recent years in attempts to measure spin-transfer torque in magnetic tunnel junctions. However, these techniques have provided only indirect measu...

Magnetoresistance and spin-transfer torque in magnetic tunnel junctions

We comment on both recent progress and lingering puzzles related to research on magnetic tunnel junctions (MTJs). MTJs are already being used in applications such as magnetic-field sensors in the read heads of disk drives, and they may also be the first device geometry in which spin-torque effects are applied to manipulate magnetic dynamics, in order to make non-volatile magnetic random access ...

Spin-transfer torque switching in magnetic tunnel junctions and spin-transfer torque random access memory

We present experimental and numerical results of current-driven magnetization switching in magnetic tunnel junctions. The experiments show that, for MgObased magnetic tunnelling junctions, the tunnelling magnetoresistance ratio is as large as 155% and the intrinsic switching current density is as low as 1.1× 10 A cm. The thermal effect and current pulse width on spin-transfer magnetization swit...