ABSTRACT
The surge of technological advances in the late 20th century associated with personal computers and the World Wide Web are now recognized as the third industrial revolution. This chapter introduces key concepts that are fundamental to the mechanisms of magnetization switching, namely, spin precession, Rabi oscillation, and spin-orbit coupling. Then, the magnetization reversal of an antiferromagnetic NiO cluster is discussed in detail, based on the numerical solution of the time-dependent Schrodinger equation. Research in ultrafast magnetization switching using femtosecond laser pulses continues to this day. Spin manipulations in magnetic nanostructures are an active research field. The chapter discusses some of the experiments that are representative of the current research. In 2002, Gerrits et al. reported the precessional magnetization reversal of a ferromagnetic permalloy. They found that the precession induced by a laser pulse could be terminated by sending another laser pulse with a sufficient time delay in between.
