W. Henggeler, N. Cavadini, A. Furrer, H. U. Güdel, K. Krämer and H. Mutka
Magnetic excitations in the quantum spin system KCuCl₃
ILL Annual Report 98, 22-23 (1999)                 

Abstract: The magnetic excitations in the double-chain compound KCuCl₃ have been investigated by inelastic neutron scattering. Above an excitation gap of 2.6 meV well-defined modes are observed which are dispersive in all directions of reciprocal space. A model based on a nonmagnetic dimerised ground state and dispersive singlet-triplet excitations can quantitatively describe the excitations.