The first observation of spin-transfer-torque phenomenon in Co/Cu multilayers

Excitation of a Magnetic Multilayer by an Electric Current

PAPER: M. Tsoi, A. G. M. Jansen, J. Bass, W.-C. Chiang, M. Seck, V. Tsoi, and P. Wyder,

“Excitation of a Magnetic Multilayer by an Electric Current”,

Phys. Rev. Lett. 80, 4281-4284 (1998).

ABSTRACT:

We describe variations in the resistance of Co/Cu multilayers, induced by means of a high current density ~10⁸ A/cm² injected into the multilayer through a point contact. We propose that the observed resistance changes are due to excitations of zero-wave-number spin waves in the magnetic layers. As predicted, such current-driven excitation of a magnetic multilayer occurs for only one direction of current flow and has a current threshold which increases linearly with the applied magnetic field.