In this paper, firstly we get entanglement degree and critical temperature T_c (whenentanglement degree is zero) in two-qubit quantum Heisenberg models H_(XX),H_(XXX) ,H_(XXZ) and H_(XYZ) .

• 本论文首先求解两个粒子的量子海森堡H_(XX),H_(XXX),H_(XXZ)和H_(XYZ)模型的纠缠度以及纠缠度为零时的临界温度T_c。