Coherent ultrafast magnetism induced by femtosecond laser pulses

Ultrafast magnetization enhancement in metallic multilayers driven by superdiffusive spin current

“…Several competing processes have been proposed for magnetization dynamics on ultrafast timescales [5][6][7][8][9][10][11][12][13] . For the trilayer systems explored here, we find that the observed magnetization dynamics in the Ni and buried Fe layer is consistent with superdiffusion of Fig.…”

“…A number of distinct models have been proposed to describe how laser excitation can couple so quickly to the spins, given that the light itself does not directly exert a significant torque on the electron spins. Most of these models are based on phonon-, electronand magnon-mediated spin-flip processes [5][6][7][8][9] , direct laser-induced spin-flips 10 or relativistic spin-light interaction 11 . Most recently, a new model based on superdiffusive spin transport has been proposed 12,13 .…”

Speed and efficiency of femtosecond spin current injection into a nonmagnetic material

“…96.100403 Two decades after the pioneering work of Beaurepaire et al [1], the fundamental processes of ultrafast laserinduced demagnetization are still heavily debated. Numerous experiments have been conducted, in addition to theoretical efforts, to elucidate the underlying microscopic mechanisms that can result in a surprisingly fast loss of magnetic order on a femtosecond (fs) time scale [2][3][4][5][6]. The microscopic mechanisms responsible for this photoinduced ultrafast loss of magnetic order can be classified as spin-flip scattering phenomena [2,7,8] and spin transport phenomena [9][10][11][12].…”

Laser-induced ultrafast demagnetization in the presence of a nanoscale magnetic domain network

“…Most commonly, the magneto-optical Kerr effect (MOKE) is exploited as a femtosecond probe of the temporal evolution of magnetization 2 . Despite some controversy about the validity of MOKE as a probe of the magnetization of an excited system on the femtosecond timescale [4][5][6][7] , significant progress has been made: the importance of subtle effects, such as direct transfer of spin angular momentum 8 or coherent magneto-optical processes 9 , have been revealed. Phenomenological and microscopic models have been proposed and further refined [10][11][12][13] .…”