Executive Summary : | The rapid growth of digital data presents a significant challenge for humanity, and spin-based magnetic data storage offers a faster, smaller, and energy-efficient solution. Magnetic spins, equivalent to bar magnets, are used to store information by converting binary "1" to binary "0" and vice versa. The key question is how fast magnetic spins can be switched deterministically. This proposal aims to model ultrafast magnetization dynamics for several FePt-based ferrimagnetic materials at elevated temperatures. To achieve this, an analytical theory and computational tools will be developed to calculate the time evolution of a magnetic spin under external sources like femtosecond laser pulses and electrical current pulses. The proposal also aims to explain experimental observations of ultrafast demagnetization and switching, and propose new experimental measurements based on theoretical and computational results. The theoretical framework will be used to derive possible non-relativistic and relativistic spin torques and evaluate their contributions numerically. The proposed approach will study ultrafast spin dynamics and switching for several ferrimagnetic alloy systems, such as (Fe100-xYx)Pt, which has the highest density of spins in the L10 phase.
The overall objective is to achieve a theoretical understanding of the ultrafast demagnetization and switching process in these ferrimagnetic alloys and, in collaboration with experimental groups in India, compare experimental results and develop new ways to manipulate spin dynamics and achieve optimal energy-efficient fast switching protocols. |