中国物理B ›› 1998, Vol. 7 ›› Issue (1): 28-37.doi: 10.1088/1004-423X/7/1/004

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BOUND POLARONS IN ASYMMETRIC QUANTUM WELLS IN AN ELECTRIC FIELD

刘自信1, 史俊杰1, 王志杰1, 翁永刚2, 潘少华3   

  1. (1)Department of Physics, Henan Normal University, Xinxiang 453002, China; (2)Department of Physics, Zhengzhou University, Zhengzhou 450052, China; (3)Institute of Physics, Academia Sinica, Beijing 100080,China
  • 收稿日期:1997-03-26 修回日期:1997-07-08 出版日期:1998-01-20 发布日期:1998-01-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China.

BOUND POLARONS IN ASYMMETRIC QUANTUM WELLS IN AN ELECTRIC FIELD

LIU ZI-XIN (刘自信)ab, WENG YONG-GANG (翁永刚)b, SHI JUN-JIE (史俊杰)ab, WANG ZHI-JIE (王志杰)ab, PAN SHAO-HUA (潘少华)c   

  1. a Department of Physics, Henan Normal University, Xinxiang 453002, China; b Department of Physics, Zhengzhou University, Zhengzhou 450052, China; c Institute of Physics, Academia Sinica, Beijing 100080,China
  • Received:1997-03-26 Revised:1997-07-08 Online:1998-01-20 Published:1998-01-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China.

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摘要： We have proposed the Hamiltonian of a polaron bound to a donor impurity in semiconductor quantum wells (QWs) in the presence of an electric field. The couplings of an electron with the confined bulk like longitudinal optical (L0) phonons, halfspace L0 phonons and interface phonons are considered. In particular, the interaction of the impurity with the various phonon modes is also included. We have calculated the ionization energy of a bound polaron in Alxl Ga1-xl As/GaAs/Alxr Ga1-xr As asymmetric and symmetric QWs. Results are obtained as a function of the barrier height (or equivalently of Al concentration x),the well width, the electric field intensities and the position of impurity in the QWs. Our numerical calculations show clearly that the interaction between the impurity and the phonon field plays an important role in screening the Coulomb interaction. It is shown that for at hin well (＜12nm), the cumulative effects of the electronphonon coupling and the impurityphonon coupling can contribute appreciably to the donor ionization energy and polarizability.

Abstract: We have proposed the Hamiltonian of a polaron bound to a donor impurity in semiconductor quantum wells (QWs) in the presence of an electric field. The couplings of an electron with the confined bulk like longitudinal optical (L0) phonons, half-space L0 phonons and interface phonons are considered. In particular, the interaction of the impurity with the various phonon modes is also included. We have calculated the ionization energy of a bound polaron in Alxl Ga1-xl As/GaAs/Alxr Ga1-xr As asymmetric and symmetric QWs. Results are obtained as a function of the barrier height (or equivalently of Al concentration x),the well width, the electric field intensities and the position of impurity in the QWs. Our numerical calculations show clearly that the interaction between the impurity and the phonon field plays an important role in screening the Coulomb interaction. It is shown that for at hin well (＜12nm), the cumulative effects of the electron-phonon coupling and the impurity-phonon coupling can contribute appreciably to the donor ionization energy and polarizability.

中图分类号:  (Polarons and electron-phonon interactions)

  • 71.38.-k
63.22.-m (Phonons or vibrational states in low-dimensional structures and nanoscale materials) 68.35.Ja (Surface and interface dynamics and vibrations)