各向异性的海森伯(s=1/2)体系的低温性质

THE DIRECTIONALLY ANISOTROPY HEISENBERG (s=1/2) SYSTEMS AT LOW TEMPERATURE

利用自旋算符的格林函数的切断近似方法,对由哈密尔顿量(?)=J(sum from ij to xy (?)_i·(?)_j+R sum from ij to z (?)_i·(?)_j)所描述的量子Heisenberg(s=1/2)体系的基态、低温行为进行了理论研究,其中包括①基态量子涨落的数值计算;②在低温下解析求解子格自发磁化、系统的能量以及磁子比热的主要温度项。

By means of the Green's function approacn for spin operators, the statistical properties such as ground state of the system and the behaviors of low temperature of the quantum Heisenberg (s = 1/2 ) systems at low temperature, described by the following Hamiltonian, (?)=J(sum from ij to xy (?)_i·(?)_j+R sum from ij to x (?)_i·(?)_j) have been discussed and calculated. These properties include (1) the quantum fluctuation at the ground states; (2) the main temperature terms of the sublattice magnetization and energy of the systems.