混合自旋反铁磁材料Y_2BaNiO_5的低激发谱

The low-lying excitation of the mixed-spin antiferromagnet Y_2BaNiO_5

采用格林函数方法,在一维自旋为1的各向异性Heisenberg模型基础上,分析了Y2BaNiO5材料的低激发谱.得到了该材料链原子的自旋关联函数,计算了材料的低激发谱在不同交换各向异性因子下的性质.结果表明,完全一维自旋为1的反铁磁材料Y2BaNiO5的基态为完全无序自旋液体态,且其间耦合作用较弱,因而可作为一维链状来处理.

Within the framework of Green function method, the low-lying excitation of the mixedspin antiferromagnet Y2BaNiO5 with spin-1 is studied in one-dimensional anisotropic Heisenberg model. The correlation function and low-lying excitation of Y2BaNiO5 with different exchange anisotropic parameter γ are obtained, and the results are close to the experimental and numerical results.