Laser-induced ultrafast spin dynamics research on magnetic nanostructures

Abstract

In this paper,taking one-magnetic-center NiO and two-magnetic-center nanostructures composed of Co and Ni as examples,we review our recent works in this field.To theoretically achieve ultrafast spin flip and transfer in magnetic nanostructures,an ultrafast spin dynamics mechanism,namely Λ process,was proposed.To properly simulate the laser-matter interaction,the accurate intragap d-states were predicted firstly through quantum chemistry calculations; then the spin localizations on magnetic atoms were analyzed considering external magnetic field and spin-orbit coupling; at last,laser pulse term was turned on to study the time history of the spin switching scenario via the Λ process.It was shown that spin flip and transfer can be achieved in a subpicosecond regime with linearly polarized light.In order to further realize checking and monitoring of the spin manipulations in magnetic molecules,a CO molecule was attached to one magnetic center to serve as an infrared marker.The calculated spin-state-dependent C-O stretching frequencies indicate that spin manipulations can be indirectly monitored through infrared spectrum experiments.