Exact soliton solution of Spin Chain with a external magnetic field in   linear wave background
  Employing a simple, straightforward Darboux transformation we construct exact N-soliton solution for anisotropic spin chain driven by a external magnetic field in linear wave background. As a special case the explicit one- and two-soliton solution dressed by the linear wave corresponding to magnon in quantum theory is obtained analytically and its property is discussed in detail. The dispersion law, effective soliton mass, and the energy of each soliton are investigated as well. Our result show that the stability criterion of soliton is related with anisotropic parameter and the amplitude of the linear wave. 
Qiu-Yan Li, Zheng-Wei Xie, Lu Li, Z. D. Li, J.Q. Liang