Neutron Scattering Study of Spin Dynamics in CsCoCl3

Abstract
Neutron profiles of spin waves in the 1d Ising-type antiferromagnet CsCoCl3 were reexamined. Instead of well-defined magnon peaks, the spin-wave spectrum consists of a band of magnon states arising from the motion of domain-wall pairs. At the magnetic zone center, the energy of this band extends from 2J(12ε) to 2J(1+2ε), whereas at the zone boundary a sharp resolution-limited peak at ω2J is observed.