磁场和耦合强度对极化子有效质量和平均声子数的影响

应用线性组合算符和幺正变换方法,研究磁场和耦合强度对极化子有效质量和平均声子数的影响.数值计算表明:极化子的有效质量随耦合强度的增加而增加,这是由于耦合强度增加时,电子与晶格振动之间的相互作用增加所致;而磁场强度增加时,有效质量是先增加,达到一个极大值后,再逐渐减少,出现共振现象.平均声子数随耦合强度的增加而增加,当磁场强度大于共振时的磁场强度时,随磁场强度的增加而减少,反之,结论相反.

The influence of coupling strength and magnetic field on effective mass and mean number of phonon of polaron

The varied relation of effective mass and mean number of phonon of polaron with coupling strength and magnetic field was derived by using the linear combination operator and unitary transformation methods. The numerical calculation indicates that the vibration frequency ~ firstly falls and late increase with increasing coupling constant a, ~ monotonous increases with increasing magnetic field strength; effective mass of polaron monotonous increases with increasing coupling strength and occurs resonance with varing magnetic field strength. In resonance point , because coupling between electron and crystal vibration is highest strength, effective mass of polaron achieves maximum. The numerical calculation also shows that mean number of phonon of polaron monotonous increases with increasing coupling strength, but decreases with increasing magnetic field strength when magnetic field strength is larger than magnetic strength of resonance point, since the farther distance from resonance point is, the weaker the interaction between electron and phonons is, conclusion is contrary when magnetic field strength is smaller than magnetic strength of resonance point.