摘要
The line shapes of dynamical spin correlation functions of the Ising-like antiferromagnetic compounds, CsCoCl3 and CsCoBr3, show asymmetry about its peak positions in which the spectral weights mainly concentrate in the low energy side. We consider a one-dimensional Ising-like Heisenberg antiferromagnetic Hamiltonian and study the dynamics of domain wall excitations in the presence of a staggered magnetic field hx along the transverse direction in order to explain those asymmetric line shapes. We obtain dynamical spin correlation functions along the magnetic field and perpendicular to it . It is shown that the line shapes of and are highly asymmetric at all values of q and hx. An excellent agreement with the experimental data throughout the whole Brillouin zone is observed upon considering a finite value of the staggered fields for both the compounds CsCoCl3 and CsCoBr3. The existence of staggered fields is justified by considering the zigzag orientations of the nonmagnetic atoms about the magnetic Co atoms.