title: Theory of Electromagnons in CuO.
abstract: We develop a theory of electromagnons in CuO by combining a symmetry analysis based on irreducible corepresentations, ab initio calculations, and simulations of spin dynamics using a model Hamiltonian and the Landau-Lifshitz-Gilbert equation. We show that the electromagnon measured in [Jones et al., Nat. Commun. 5, 3787 (2014)] with the electric field along the [101] direction originates from a magnetoelectric coupling mediated by Dzyaloshinskii-Moriya interactions and consists of a rigid rotation of the Cu spins around the axis defined by the electric field. Furthermore we predict the existence of a second electromagnon originating from exchange striction and coupled to electric fields along the [010] direction in the AF2 phase.
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Kun
authors.initials: K
authors.lastname: Cao
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Feliciano
authors.initials: F
authors.lastname: Giustino
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: Paolo G
authors.initials: PG
authors.lastname: Radaelli