抛物量子阱中束缚极化子的温度效应  

Temperature Effect of the Bound Polaron in a Parabolic Quantum Well

作　　者：红兰[1] 戈君[1] 刘达权 双山 HONG Lan;GE Jun;LIU Da-quan;SHUANG Shan(School of Physics and Electronic In formation,Hulunbuir University,Hulunbuir 021008,China)

机构地区：[1]呼伦贝尔学院物理与电子信息学院,内蒙古呼伦贝尔021008

出　　处：《量子光学学报》2021年第4期352-358,共7页Journal of Quantum Optics

基　　金：呼伦贝尔学院服务地方重点项目(2019FDZD04);呼伦贝尔学院优秀科研成果后期资助项目(2021HQPT126);教育部高等教育司2020年产学合作协同育人项目(202002029015)。

摘　　要：理论研究了抛物量子阱中强耦合束缚极化子的温度效应,采用线性组合算符和幺正变换相结合的方法得到了极化子基态能量和基态结合能的表达式。极化子基态能量和基态结合能分别是振动频率、电子-声子耦合强度、库仑束缚势强度、阱宽以及阱深的函数。在有限温度下,电子-声子系统将不再完全处于基态,晶格振动不但激发实声子,同时也使电子受到激发,极化子的性质主要由电子-声子系统对各种状态的统计平均值来决定。通过理论计算还得到了极化子平均声子数的表达式,极化子平均声子数是振动频率的函数,结合量子统计学,得到极化子基态能量和基态结合能与温度之间的函数关系。通过数值计算得到:极化子基态能量和基态结合能都是温度的增函数。当温度取定值时:随着电子-声子耦合强度、库仑束缚势强度、阱宽的增加,极化子基态能量减小,基态结合能增大;随着阱深的增大极化子基态能量增大,基态结合能减小。The temperature effect of the strong coupling bound polaron in a parabolic quantum well is studied theoretically,and the expressions of the polaron ground state energy and the ground state binding energy are derived by using the linear combination operator and the unitary transformation methods.The ground state energy and ground state binding energy of polaron are functions of the vibration frequency,electron phonon coupling strength,Coulomb bound potential strength,well width and well depth,respectively.At finite temperature,the electron phonon system will no longer be complete in the ground state.The lattice vibration not only excites the real phonon,but also excites the electron.The properties of polaron are mainly determined by the statistical average of various states of electron phonon system.The expression of the average phonon number of polaron is also obtained through theoretical calculation.Combined with quantum statistics,the functional relationship between the ground state energy and ground state binding energy of polaron and temperature is obtained.By numerical calculation,the polaron ground state energy and ground state binding energy are increasing functions of temperature.When the temperature is set to a fixed value,as the electron-phonon coupling strength,Coulomb bound potential strength and well width increase,the ground state energy of the polaron decreases and the ground state binding energy increases.With the increase of the well depth,the ground state energy of the polaron increases,and the ground state binding energy decreases.

关 键 词：抛物量子阱 束缚极化子 基态能量 基态结合能 温度效应 

分 类 号：O471[理学—半导体物理]