Nonequilibrium magnons from hot electrons in antiferromagnetic systems

We describe a nonthermal magnon activation mechanism in antiferromagnetic (AFM) systems via locally equilibrated spin-unpolarized hot electrons excited by an ultrafast intense laser pulse. We employ a quantum kinetic equation that takes into account a direct electron-magnon scattering channel in eit...

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Bibliographic Details
Main Authors: Marion M. S. Barbeau, Mikhail Titov, Mikhail I. Katsnelson, Alireza Qaiumzadeh
Format: Article
Language:English
Published: American Physical Society 2023-06-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.5.L022065
Description
Summary:We describe a nonthermal magnon activation mechanism in antiferromagnetic (AFM) systems via locally equilibrated spin-unpolarized hot electrons excited by an ultrafast intense laser pulse. We employ a quantum kinetic equation that takes into account a direct electron-magnon scattering channel in either bulk AFM metal or at the interface of the AFM/normal-metal heterostructure. The mechanism is responsible for the nonequilibrium population of AFM magnon modes on a subnanosecond timescale, which are formed shortly after quasithermalization of hot electrons by Coulomb interactions. Nonequilibrium magnon populations can be additionally manipulated by applying an external magnetic field. Our work paves the way toward spin dynamics control in AFM systems via the ultrafast manipulation of out-of-equilibrium magnon excitations.
ISSN:2643-1564