载流子与铁磁物质耦合系统的严格对角化解与相干态变分方法  

Exact diagonalization solution and coherent state variational method of the coupling system of carrier and ferromagnetic material

作　　者：黄书文[1] 刘涛[1] 范云霞[1] 汪克林[1] 

机构地区：[1]西南科学技术大学理学院,绵阳621010

出　　处：《物理学报》2007年第1期491-499,共9页Acta Physica Sinica

基　　金：川省教育厅基金(批准号:041139)资助的课题~~

摘　　要：引用Schwinger的角动量谐振子理论将载流子与铁磁物质耦合系统变换为载流子与两类玻色子耦合的问题,对铁磁物质中束缚极化子的存在决定于介质中有无杂质势的规律进行了严格对角化求解.得到的结论与普遍的看法一致,与相干态变分方法计算的基态能结果十分吻合,两种方法得到的波矢定性上也吻合,说明了相干态变分方法的可靠性和有较高的准确性,严格对角化解方法也可为其他的近似方法提供检验基础.The problem of the coupling system of carrier and ferromagnetic material has bee.n transformed into that of the coupling system of carrier and two kinds of Bosons by using Schwinger＇ s oscillator theory of angular momentum. That the existence of bound polaron in ferromagnetic material depends on the existence of impurity potential in this material is solved exactly by diagonalization and the conclusion obtained is in agreement with the general view point of other works. The values of the energy of ground state obtained by the exact solution and coherent state variation method is agree quite well. The qualitative characters of state vector given by both methods are consistent. The results shows that the coherent state variation method is valid and precise enough for this problem. Exact solution method will provide a basis to check the validity of any other approximate methods.

关 键 词：束缚极化子 杂质势 铁磁物质 严格对角化解 

分 类 号：O482.5[理学—固体物理]