Dyson–Maleev theory of an X X Z ferrimagnetic spin chain with single-ion anisotropy*

Project supported by the National Natural Science Foundation of China (Grant No. 10774035) and the Qianjiang RenCai Program of Zhejiang Province, China (Grant No. 2007R0010).

Chen Yu-Ge1, Li Yin-Xiang2, †, Tian Li-Jun1, Chen Bin2, ‡
       

(color online) Energy spectrums with different XXZ anisotropic parameters λ = 1.0 (red solid), λ = 1.1 (black dotdashed), λ = 1.2 (green dashed) and λ = 1.3 (blue dotted) at zero temperature.