基于Pekar类型变分法的高斯函数型限定势阱量子点中电子的跃迁  

Electronic transition in a Gaussian functional confinement potential well disk quantum dot based on Pekar-type variational method

作　　者：赵玉伟 尹洪武[1] 额尔敦朝鲁[1] ZHAO Yu-wei;YIN Hong-Wu;Eerdunchaolu(Institute of Condensed Matter Physics,Hebei Normal University of Science & Technology,Qinhuangdao 066004, China)

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

出　　处：《光电子．激光》2019年第2期215-220,共6页Journal of Optoelectronics·Laser

基　　金：河北省自然科学基金(E2013407119)资助项目

摘　　要：分别选取抛物线型限定势阱和高斯函数型限定势阱描写盘状量子点中电子的横向限定势和纵向限定势,采用Pekar类型变分法推导出了电子的基态和激发态能量,并基于费米黄金规则讨论了在磁场作用下电子的跃迁几率。结果表明,高斯函数型限定势阱比抛物线型限定势阱更能精准反映量子点中真实的限定势;量子点的厚度对电子跃迁几率的影响显著;电声耦合强度α、磁场的回旋频率ω_c、抛物线型限定势阱范围R_0、高斯函数型限定势阱的阱深V_0和阱宽L等对电子跃迁几率Q的影响的量度和变化规律方面差异较大。The parabolic confinement potential well(PCPW) and Gaussian functional confinement potential well(GFCPW) are selected to describe the transverse and longitudinal confinement potentials of the electron in the disk quantum dot(DQD),respectively.The ground and exited state energies of the electron are derived by using Pekar-type variational method,then the electronic transition affected by a magnetic field is discussed based on the Fermi golden rule.The results indicate that the ground-state energy E0 and the excited state energy E1 of the electr on increase with decreasing the range R0 of the PCPW.The absolute values |E0| and |E1|increase with increasing the strength of the electron-phonon coupling(SEPC)α,the well width L and the well depth V0 of the GFCPW,respectively.The transition probability P decreases with decreasing R0 of the PCPW when α>6.0(strong coupling) and increases with decreasing the SEPC α.The transition probability P is the increasing function of the well width L of the AGFCP when L is large(L>1.3rp).The probability P oscillates and decreases with the decreasing well width L of the AGFCP when L is small(L<1.3rp).The transition probability P decreases with increasing the well depth V0 of the AGFCP when L is fixed.The transition probability P oscillates with changing the magnetic-field cyclotron frequency ωc,and the magnetic field is not only an indispensable condition for the induced electron transition,but also has a strong regulatory function on the transition probability.The GFCPW reflects the real confinement potential more accurately than PCPW.The influence of the thickness of the quantum dot on the electronic transition is significant and cannot be ignored.There is a large difference in the influence of the strength of the electron-phonon coupling α,the range R0 of the PCPW,the magnetic-field cyclotron frequency ωc,the well width L and the well depth V0 of the GFCPW on the electronic transition probability P,respectively.

关 键 词：盘状量子点 Pekar类型变分法 高斯函数型限定势阱 跃迁几率 

分 类 号：O469[理学—凝聚态物理]