摘要
利用线性组合算符和幺正变换相结合的方法,推导出极化子基态与耦合强度和磁场强度的关系。数值计算表明:当磁场强度给定时,随着耦合常数α的增加,振动频率λ先减小后增大;基态能量E0单调下降;自陷能E0tr单调增大;Landau能E0L先增大,达到最大值后又下降。当耦合强度给定时,随着磁场强度的增大,λ单调增大,且α愈小,λ增加愈快;基态能量E0随磁场强度的增大而增大;自陷能E0tr随着磁场强度的增大而略有增加;Landau能E0L随着磁场强度的增大先增大,达到最大值后,又开始下降。
With the development of technological and experimental techniques , crystals with all kinds of dimension and shape have been made by experiment, which has brought out a large market for the apply of new materials. So there is continuing interests in polaron. LeeLowPines calculated the groundstate energy of polaron by a variational technique. Huybrechts calculated the energy of the groundstate and the first internal excited state of the optical polaron for different values of the electronphonon coupling. N.Tokuda studied the dependence of groundstate energy, effective mass and the mean number of polaron on the coupling constant by using the unitary transformation and the method of a lagrange multiplier. Larsen got the groundstate energy of the twodimension magnetoplaron by using forthorder perturbationtheoretic method. Wei et al. investigated the cyclotronresonance mass and frequency of the interface polaron by using Feyman path integration method. Recently, Catandella et al. studied the properties of polaron in onedimension Holstein molecular crystals by using a new variational method, which chosen the linear overlap of Bloch wave of large polaron and small polaron as a trial wavefunction, obtained the variational regularities of the groundstate energy, mass and the mean number of polaron with coupling constant. We also did some works on polaron by using Huybrechts' method. But all works were based on only one considering either magnetic field or coupling strength,respectively. This paper is going to illustrate the common influence of magnetic field and coupling strength on the properties of polaron.The variational relations of the groundstate energy, selftrapping energy and Landau energy with coupling constant and cyclotronresonance frequency are derived by using linearcombination operator method. Numerical calculation indicates that the vibration frequency λ firstly falls, arriving to a minimum value, late increases with increasing coupling constant α; λ monotonously rises with increasing cyclotronresonance frequency ωc;the groundstate energy E0 decrease with increasing α and monotonous rises with increasing ωc;the selftrapping energy E0tr increases with increasing α and ωc;Landau energy E0L firstly increases to a maximum and then fall with increasing α;E0L firstly rises to maximum also and then decreases with increasing ωc.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2003年第3期243-246,共4页
Chinese Journal of Luminescence
基金
内蒙古高校重大科研基金资助项目(ZD0018)
