Domain-wall excitations in the one-dimensional spin-1/2 fully anisotropic Ising-like antiferromagnet

We consider the S = 1/2 Ising-like, fully anisotropic Heisenberg antiferromagnetic Hamiltonian in one dimension and study the dynamics of domain-wall excitations using perturbation theory. It is shown that the domain walls can form bound states. The transverse correlation function S-xx(q,omega) is calculated in first-order perturbation theory and the zone-centre lineshape is found to be asymmetric towards lower energy. A comparison of the results with earlier theories as well as experimental results on CsCoCl3 and CsCoBr3 is made.