无限深量子阱中强耦合极化子的基态结合能

研究了无限深量子阱中极化子的基态性质,采用线性组合算符和变分相结合的方法导出了强耦合极化子的振动频率λ、基态能量E₀和基态结合能E_b,讨论了阱宽L和电子-LO声子耦合强度α对强耦合极化子的振动频率λ、基态能量E₀和基态结合能E_b的影响。通过数值计算,结果表明:强耦合极化子的振动频率和基态结合能随阱宽L的增大而减小,随电子-LO声子耦合强度α的增强而增大;基态能量随阱宽L的增大而减小,其绝对值随电子-LO声子耦合强度α的增强而增大;当量子阱阱宽L趋近于无限大和无限小两种极限情况下,分别与三维和二维极化子的结果相一致。

Ground State Binding Energy of Strong Coupling Polaron in a Infinite Quantum Well

With the development of the growth techniques of the semiconductor, the well performanced heterostructures, quantum well and superlattice have been prepared,which is the great breach in Semiconductor physics and material science.The problem of confined electron in a quantum well(QW) has attracted much interest from physicists in recent years. Zhao et al. calculated the ground state, the first excited state and the transition energy of the electron(or hole) in the GaAs/Al_0.3Ga_0.7As parabolic quantum well by using a mo-(dified) Lee-Low-Pines variational method. Chen et al. investigated polaronic effects in a quantum well by using the Landau-Perkar theory. Comas et al. and Rücker et al. calculated self-energy of polaron and mageneto-(polaron) in a quantum well by use of the standard perturbation-theory. Chou et al. studied the ground state binding energy of hydrogenic impurity in a quantum well by using a general perturbative method proposed by Lee and Mei. Shen et al. discussed the binding energies of the hydrogenic donor ground state in a GaAs-Ga_1-x-Al_xAs quantum well of finite barrier height in presence of a magnetic field, which is taken to be parallel to the growth axis of the quantum-well structure by using strong-perturbation theory and pertubative-variational approach. Ren et al. calculated the ground-state energy of a polaron in parabolic quantum well in the presence of a Coulomb potential by using Feynman-Haken path integral theory.Eerdunchaolu et al. studied the tempe-(rature) dependence of the properties of electron-bulk LO phonon interaction system in a quantum well within (the electric-magnetic) fields along the growth axis by using variational wave-function and harmonic oscillator (operator) algebra method.The properties of the polaron in a quantum well are seldom investigated by using a linear-combination-(operator) method. In this paper, the properties of ground state of the polaron in an finite quantum well were investigated. The vibration frequency, ground state energy and ground state binding energy of the strong-coupling polaron in an infinite quantum well, the effects of well width L and electron-LO phonon coupling strength α on the vibration frequency λ,ground state energy E₀ and ground state binding energy E_b of the strong-coupling polaron were discussed by using a linear-combination-operator and variational method. Numerical calculation (illustrates) that the vibration frequency and ground state binding energy of strong-coupling polaron in an infinite quantum well will decrease with increasing well width L and increase with increasing the coupling strength α;the ground state energy will decrease with increasing L and its absolute value will increase with increasing coupling strength α; our results approach those of 2D and 3D polarons respectively in the limits of small and large well width L.