反铁磁体KCuF_3中的非线性问题

Nonlinear Problems in Antiferromagnet KCuF_3

应用相干态方案和依赖时间的变分原理，从反铁磁体ＫＣＵＦ３的哈密顿量得到形式为非线性偏微分方程组的运动方程．使用多标度变换方法，将运动方程化为包络函数方程组。发现幅函数满足非线性薛定谔方程，得到了反铁磁体ＫＣｕＦ３中的孤子解、周期波解、非线性本征局域模等．

Employing the coherent state ansatz and the time dependent variational principle,the two partial differential equations of motion are obtained from the Hamiltonian of antiferromagnet KCuF3. Using the method of multiple scales,these equations are reduced into the envolope function equations and the amplitude function is satisfied a nonlinear Schrodinger equation.The solitons,the periodic wave solutions and nonlinear intrinsic localized modes are investigated.