Minimum Field Strength in Ultrafast Magnetization Reversal

Ultrafast magnetic field pulses as short as 2 ps are able to reverse the magnetization in thin in-plane magnetized cobalt films. The field pulses are applied in the plane of the film and their direction encompasses all angles with the magnetization. At right angle to the magnetization maximum torque is exerted on the spins. In this geometry a precessional magnetization reversal can be triggered by fields as small as 184 kA/m. Applications in future ultrafast magnetic recording schemes can be foreseen