非对称量子点中磁极化子性质的磁场和温度依赖性  

Magnetic field and temperature dependence of the properties of the magnetopolaron in an asymmetric quantum dot

作　　者：额尔敦朝鲁[1] 于若蒙[2] 

机构地区：[1]河北科技师范学院凝聚态物理研究所,秦皇岛066004 [2]华中科技大学物理系,武汉430074

出　　处：《物理学报》2008年第11期7100-7107,共8页Acta Physica Sinica

基　　金：河北省自然科学基金(批准号:A2008000463);河北科技师范学院博士基金(批准号:2006D001)资助的课题~~

摘　　要：采用Tokuda线性组合算符法和Lee-Low-Pines变换法,研究了温度和磁场对非对称抛物量子点中强耦合磁极化子性质的影响,简捷地得到了作为量子点的横向受限强度ω1、纵向受限强度ω2、电子-声子耦合强度α、外磁场的回旋频率ωc和温度参数γ的函数的磁极化子的振动频率λ、基态能量E0和有效质量m*的表达式.数值计算结果表明:λ和m*随ω1,ω2,ωc和α的增加而增大,随温度T的升高而减小.E0随ω1,ω2,ωc,α和γ的变化规律与磁极化子所处的状态性质有着密切的关系.E0的正负号不仅与ω1,ω2,ωc和α的取值有关,而且还与γ的取值关系密切.但温度T对λ,m*和E0的影响只是在高温(γ<0.4)时较明显,而在γ>0.4的低温下并不明显.The influence of the magnetic field and temperature on the properties of the strong-coupling magnetopolaron in an asymmetric quantum dot is studied by using the Tokuda＇s linear-combination operator and the Lee-Low-Pines variational method.The expressions for the vibration frequency λ,ground state energy E0 and the effective mass m of the magnetopolaron as a function of the transverse effective confinement strength ω1,the longitudinal effective confinement strength ω2,the electron-phonon coupling strength α,the cyclotron frequency ωc and the temperature parameter γ are derived.Numerical results indicate that λ and m of the magnetopolaron will increase with increasing ω1,ω2,ωc and α,and will decrease with increasing temperature T.The value of E0 changing with ω1,ω2,ωc,α and γ are srongly related to the propties of the state of the magnetopolaron.The signs of positeve and negative E0 relate not only to the value of ω1,ω2,ωc and α but also to the value of γ.However,only on the condition of higher temperature（γ〈0.4）,the influence of temperature on λ,m and E0 of the magnetopolaron is obvious.

关 键 词：非对称量子点 强耦合磁极化子 磁场和温度依赖性 

分 类 号：O471.1[理学—半导体物理] TN304.21[理学—物理]