title: Angular momentum conservation for coherently manipulated spin polarization in photoexcited NiO: an ab initio calculation.
abstract: In an ultrafast laser-induced magnetization-dynamics scenario we demonstrate for the first time an exact microscopic spin-switch mechanism. Combining ab initio electronic many-body theory and quantum optics analysis we show in detail how the coherently induced material polarization for every elementary process leads to angular-momentum exchange between the light and the irradiated antiferromagnetic NiO. Thus we answer the long-standing question where the angular momentum goes. The calculation also predicts a dynamic Kerr effect, which provides a signature for monitoring spin dynamics, by simply measuring the transient rotation and ellipticity of the reflected light.
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Box 3049, 67653 Kaiserslautern, Germany. lefkidis@physik.uni-kl.de
authors.forename: Georgios
authors.initials: G
authors.lastname: Lefkidis
authors.forename: G P
authors.initials: GP
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Hübner