title: Lifetimes of antiferromagnetic magnons in two and three dimensions: experiment, theory, and numerics.
abstract: A high-resolution neutron spectroscopic technique is used to measure momentum-resolved magnon lifetimes in the prototypical two- and three-dimensional antiferromagnets Rb(2)MnF(4) and MnF(2), over the full Brillouin zone and a wide range of temperatures. We rederived theories of the lifetime resulting from magnon-magnon scattering, thereby broadening their applicability beyond asymptotically small regions of wave vector and temperature. Corresponding computations, combined with a small contribution reflecting collisions with domain boundaries, yield excellent quantitative agreement with the data. Comprehensive understanding of magnon lifetimes in simple antiferromagnets provides a solid foundation for current research on more complex magnets.
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany. bayrakci@fkf.mpg.de
authors.forename: S P
authors.initials: SP
authors.lastname: Bayrakci
authors.forename: D A
authors.initials: DA
authors.lastname: Tennant
authors.forename: Ph
authors.initials: P
authors.lastname: Leininger
authors.forename: T
authors.initials: T
authors.lastname: Keller
authors.forename: M C R
authors.initials: MC
authors.lastname: Gibson
authors.forename: S D
authors.initials: SD
authors.lastname: Wilson
authors.forename: R J
authors.initials: RJ
authors.lastname: Birgeneau
authors.forename: B
authors.initials: B
authors.lastname: Keimer