title: Intrinsic coupling of orbital excitations to spin fluctuations in Mott insulators.
abstract: We show how the general and basic asymmetry between two fundamental degrees of freedom present in strongly correlated oxides, spin and orbital, has very profound repercussions on the elementary spin and orbital excitations. Whereas the magnons remain largely unaffected, orbitons become inherently coupled with spin fluctuations in spin-orbital models with antiferromagnetic and ferro-orbital ordered ground states. The composite orbiton-magnon modes that emerge fractionalize again in one dimension, giving rise to spin-orbital separation in the peculiar regime where spinons are faster than orbitons.
authors: IFW Dresden, P.O. Box 27 01 16, D-01171 Dresden, Germany.
authors: Krzysztof
authors: K
authors: Wohlfeld
authors: Maria
authors: M
authors: Daghofer
authors: Satoshi
authors: S
authors: Nishimoto
authors: Giniyat
authors: G
authors: Khaliullin
authors: Jeroen
authors: J
authors: van den Brink