Atomistic spin model simulations are immensely useful in determining temperature dependent magnetic prop- erties, but are known to give the incorrect dependence of the magnetization on temperature compared to exper- iment owing to their classical ori
gin. We find a single parameter rescaling of thermal fluctuations which gives quantitative agreement of the temperature dependent magnetization between atomistic simulations and experi- ment for the elemental ferromagnets Ni, Fe, Co and Gd. Simulating the sub-picosecond magnetization dynam- ics of Ni under the action of a laser pulse we also find quantitative agreement with experiment in the ultrafast regime. This enables the quantitative determination of temperature dependent magnetic properties allowing for accurate simulations of magnetic materials at all temperatures.
Synthetic ferrimagnets are composite magnetic structures formed from two or more anti- ferromagnetically coupled magnetic sublattices with different magnetic moments. Here we report on atomistic spin simulations of the laser-induced magnetization dyn
amics on such synthetic ferrimag- nets, and demonstrate that the application of ultrashort laser pulses leads to sub-picoscond magnetization dynamics and all-optical switching in a similar manner as in ferrimagnetic alloys. Moreover, we present the essential material properties for successful laser-induced switching, demonstrating the feasibility of using a synthetic ferrimagnet as a high density magnetic storage element without the need of a write field.
