Switching by point-contact spin injection in a continuous film

Abstract
Spin-polarized currents injected through a point-contact into a continuous Co/Cu/Co trilayer film can reversibly switch the magnetization of small magnetic bits in the top Co layer. The magnetic states written depend on the polarity of the injection currents, and remain stable at room temperature. The reversible writing can be achieved for a wide range of contact resistances with a well-defined voltage for the reversal.