Magnon activation by hot electrons via non-quasiparticle states

Abstract

We consider the situation when a femtosecond laser pulse creates a hot electron state in half-metallic ferromagnet (e. g. ferromagnetic semiconductor) on a picosecond timescale but do not act directly on localized spin system. We show that the energy and magnetic moment transfer from hot itinerant electrons to localized spins is facilitated by the so-called non-quasiparticle states, which are the scattering states of a magnon and spin-majority electron. The magnon distribution is described by a quantum kinetic equation that we derive using the Keldysh diagram technique. In a typical ferromagnetic semiconductor such as EuO magnons remain essentially in non-equilibrium on a scale of the order of microsecond after the laser pulse.

arXiv comment8 pages, 2 figures

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Cited by in corpus (3)

• Ultrafast Demagnetization through Femtosecond Generation of Non-thermal Magnons
• Transient quantum isolation and critical behavior in the magnetization dynamics of half-metallic manganites
• Nonequilibrium magnons from hot electrons in antiferromagnetic systems