中国物理B ›› 2009, Vol. 18 ›› Issue (5): 1935-1941.doi: 10.1088/1674-1056/18/5/035

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Bound polaron in quantum dot quantum well structures

邢雁, 王志平, 王旭   

  1. Department of Physics, Inner Mongolia University, Hohhot 010021, China
  • 收稿日期:2008-04-22 修回日期:2008-09-19 出版日期:2009-05-20 发布日期:2009-05-20
  • 基金资助:
    Project supported by Universities Program of Inner Mongol of China (Grant No NJZZ07008) and the Natural Science Foundation of Inner Mongol of China (Grant No 200607010105).

Bound polaron in quantum dot quantum well structures

Xing Yan(邢雁), Wang Zhi-Ping(王志平)†, and Wang Xu(王旭)   

  1. Department of Physics, Inner Mongolia University, Hohhot 010021, China
  • Received:2008-04-22 Revised:2008-09-19 Online:2009-05-20 Published:2009-05-20
  • Supported by:
    Project supported by Universities Program of Inner Mongol of China (Grant No NJZZ07008) and the Natural Science Foundation of Inner Mongol of China (Grant No 200607010105).

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摘要： The problem of bound polarons in quantum dot quantum well (QDQW) structures is studied theoretically. The eigenfrequencies of bulk longitudinal optical (LO) and surface optical (SO) modes are derived in the framework of the dielectric continuum approximation. The electron--phonon interaction Hamiltonian for QDQW structures is obtained and the exchange interaction between impurity and LO-phonons is discussed. The binding energy and the trapping energy of the bound polaron in CdS/HgS QDQW structures are calculated. The numerical results reveal that there exist three branches of eigenfrequencies of surface optical vibration in the CdS/HgS QDQW structure. It is also shown that the binding energy and the trapping energy increase as the inner radius of the QDQW structure decreases, with the outer radius fixed, and the trapping energy takes a major part of the binding energy when the inner radius is very small.

Abstract: The problem of bound polarons in quantum dot quantum well (QDQW) structures is studied theoretically. The eigenfrequencies of bulk longitudinal optical (LO) and surface optical (SO) modes are derived in the framework of the dielectric continuum approximation. The electron--phonon interaction Hamiltonian for QDQW structures is obtained and the exchange interaction between impurity and LO-phonons is discussed. The binding energy and the trapping energy of the bound polaron in CdS/HgS QDQW structures are calculated. The numerical results reveal that there exist three branches of eigenfrequencies of surface optical vibration in the CdS/HgS QDQW structure. It is also shown that the binding energy and the trapping energy increase as the inner radius of the QDQW structure decreases, with the outer radius fixed, and the trapping energy takes a major part of the binding energy when the inner radius is very small.

Key words: bound polaron, quantum dot, quantum well

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

  • 71.38.-k
73.21.La (Quantum dots) 73.21.Fg (Quantum wells) 68.65.Hb (Quantum dots (patterned in quantum wells)) 68.65.Fg (Quantum wells) 63.22.-m (Phonons or vibrational states in low-dimensional structures and nanoscale materials)