Ultrafast light-induced magnetization dynamics in ferromagnetic semiconductors

摘要

We develop a theory of the magnetization dynamics triggered by ultrafastoptical excitation of ferromagnetic semiconductors. We describe the effects ofthe strong carrier spin relaxation on the nonlinear optical response by usingthe Lindblad semigroup method. We demonstrate magnetization control duringfemtosecond timescales via the interplay between circularly polarized opticalexcitation, hole-spin damping, polarization dephasing, and the Mn-hole spininteractions. Our results show a light-induced magnetization precession andrelaxation for the duration of the optical pulse.