Lu, J , Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China
部门归属:
[Lu, J; Zhou, L; Kuang, LM] Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China; [Lu, J; Sun, CP] Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China
英文摘要:
We study the nonlinear dynamics of collective excitation in an N-site XXZ quantum spin chain, which is manipulated by an oblique magnetic field. We show that, when the tilted field is applied along the magic angle, theta(0)=+/- arccos root 1/3, the anisotropic Heisenberg spin chain becomes isotropic and thus an freely propagating spin wave is stimulated. Also, in the regime of tilted angles larger and smaller than the magic angle, two types of nonlinear excitations appear: bright and dark solitons.