Prof. dr. Andrei Kirilyuk: Balance of angular momentum and magnetization switching in ferrimagnetic alloys
|Wanneer:||do 30-10-2014 10:00 - 11:00|
Many peculiarities of magnetization dynamics are related to the fact that a certain amount of angular momentum is associated with magnetic moments. Here I would like to consider the mechanism responsible for the ultrafast heat-induced switching of the magnetization in ferrimagnetic alloys and multilayers. This switching is found to follow a counterintuitive pathway via a ferromagnetic state, which crucially depends on the angular momentum balance of the two opposite sublattices. It appeared that the transient state is due to two reasons: (i) considerably different demagnetization times of the RE and TM sublattices, and (ii) angular-momentum conservation and its transfer between the sublattices . Thus, most interesting, this switching is fully due to the non-equilibrium behavior of the magnetization.