WANG Chun-yan, XIAO Jing-lin. Influence of Coulomb Field on Properties of the Excited State of Strong-coupling Bound Polaron in a Quantum Dot[J]. Chinese Journal of Luminescence, 2007,28(4): 493-497
WANG Chun-yan, XIAO Jing-lin. Influence of Coulomb Field on Properties of the Excited State of Strong-coupling Bound Polaron in a Quantum Dot[J]. Chinese Journal of Luminescence, 2007,28(4): 493-497DOI:
With the development of molecular beam expitaxy(MBE) technology and metal organic chemical vapor deposition(MOCVD) technology
there has been great interest in investigating quantum dot in both material science and condensed state physics field.Due to size of quantum dot was small
they had a series of new and serious character
for example
quantum size effect
quantum coherent effect
quantum tunnel effect
Coulomb resistance effect and surface effect
etc.
these had brought infinite chance and hope on development and use of new materials.The properties of the polaron in a quantum dot have been studied by many investigators theoretically and experimentally.In recent years
with the study of the properties of bound polaron in a quantum dot
people have paid more attention to them.The vibrational frequency
the average number of optical phonons and the interaction energy of bound polaron in a parabolic quantum dot have been discussed using the linear combination operator method by the present authors.However
the properties of excited state of bound polaron in a quantum dot have not been investigated by a linear combination operator method so far.The purpose of the present paper is to explore the effect of Coulomb bound potential on the properties of the bound polaron in a quantum dot.With the strong-coupling between the electron and bulk LO phonon included
we obtain an expression for the vibrational frequency
the first internal excited state energy
the excitation energy and the resonance frequency of the strong-coupling bound polaron in a quantum dot by using the linear combination operator method.The relation of these quantities with the effective confinement length of the quantum dot
the Coulomb bound potential and the electron-phonon coupling strength were discussed.Numerical calculations show that the vibrational frequency
the first internal excited state energy
the excitation energy and the resonance frequency of the strong-coupling bound polaron in a quantum dot will strongly increase with decreasing the effective confinement length of the quantum dot
and will increase with increasing the Coulomb bound potential and the electron-phonon coupling strength.