Speaker
Ms
Olha Boliasova
(Donetsk Institute for Physics and Engineering, the NAS of Ukraine)
Abstract
A microscopic model is used to describe longitudinal spin excitations in a two-sublatticeantiferromagnet (AFM). Thediagrammatic technique for spin operators allows to overcome limitations typical for phenomenological approaches. We have obtained an expression for the longitudinal dynamic spin susceptibility χzz(q,ω) applicable in all regions of frequency ω and wave vector q space beyond the hydrodynamical and critical regimes.Virtual processes that determine the AFM longitudinal dynamicalsusceptibility are considered. It is shown that the frequencydetermined by the excitation/absorption of two magnonslies energetically above transverse spin wave frequency and it remains even in the absence of thermal excitations.
Primary authors
Ms
Olha Boliasova
(Donetsk Institute for Physics and Engineering, the NAS of Ukraine)
Prof.
Vladimir Krivoruchko
(Donetsk Institute for Physics and Engineering, the NAS of Ukraine)
