ELECTRIC FIELD EFFECTS ON POLARONS WITH SPATIALLY DEPENDENT MASS IN PARABOLIC QUANTUM WELLS

2004 ◽  
Vol 18 (22) ◽  
pp. 2991-2999 ◽  
Author(s):  
FENG-QI ZHAO ◽  
ZI-ZHENG GUO
Keyword(s):  
Electric Field ◽  
Quantum Wells ◽  
Effective Mass ◽  
Energy Levels ◽  
Longitudinal Optical ◽  
Optical Phonons ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Dependent Mass ◽  
Parabolic Quantum Wells

The free polaron energy levels in finite GaAs / Al x Ga 1-x As parabolic quantum wells have been investigated by a modified variational method. The effect of the electric field, the electron-phonon interaction including the longitudinal optical phonons and the four branches of interface optical phonons, and the effect of spatial dependent effective mass have been considered in the calculation. The dependence of the energies of free polarons on the alloy composition x is given. The numerical results for finite GaAs / Al x Ga 1-x As parabolic quantum wells are obtained and discussed. The results show that the effect of the electric field and the interface optical phonons as well as the longitudinal optical phonons on the energy levels is obvious. One can find that the effect of the spatially dependent effective masses on the energy levels in finite parabolic quantum wells is considerable except for large well width. Thus, the electron-phonon interaction and the effect of the spatially dependent effective mass should not be neglected for the study of the electron state problem in finite parabolic quantum wells.

INFLUENCE OF ELECTRIC FIELD ON THE BINDING ENERGY OF HYDROGENIC IMPURITY WITH SPATIALLY DEPENDENT MASS IN NITRIDE PARABOLIC QUANTUM WELLS

2007 ◽  
Vol 21 (05) ◽  
pp. 279-286 ◽  
Author(s):  
FENG-QI ZHAO ◽  
JIAN GONG
Keyword(s):  
Binding Energy ◽  
Electric Field ◽  
Quantum Wells ◽  
Ground State ◽  
Quantum Confinement Effect ◽  
Energy Levels ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Dependent Mass ◽  
Parabolic Quantum Wells

The ground state and binding energies of the hydrogenic impurity in a finite GaN/Al x Ga 1-x N parabolic quantum well (PQW) are investigated by using variational method. The effect of an electric field and spatial dependence effective mass (SDEM) are considered in the calculation. The results indicate that the effect of the SDEM on the energy levels is more obvious in the case of the narrower well width L. The effects decrease with increasing L, and tend to zero. The electric field shifts the energy levels towards lower energies with increasing well width L. Furthermore the ground state binding energy of the hydrogenic impurity in GaN/Al x Ga 1-x N PQWs is larger than that in GaAs/Al x Ga 1-x As PQWs. Therefore, we affirm that there is stronger quantum confinement effect in GaN/Al x Ga 1-x N PQW.

scholarly journals Многократное изменение электрон-фононного взаимодействия в квантовых ямах с диэлектрически различными барьерами

2022 ◽  
Vol 56 (1) ◽  
pp. 101
Author(s):  
А.Ю. Маслов ◽  
О.В. Прошина
Keyword(s):  
Quantum Wells ◽  
Charged Particles ◽  
Strong Interactions ◽  
Asymmetric Structure ◽  
Optical Phonons ◽  
Phonon Modes ◽  
Phonon Interaction ◽  
Barrier Materials ◽  
Electron Phonon Interaction ◽  
Order Of Magnitude

Abstract The specific features of the interaction of charged particles with polar optical phonons have been studied theoretically for quantum wells with the barriers that are asymmetric in their dielectric properties. It is shown that the interaction with interface phonon modes makes the greatest contribution in narrow quantum wells. The parameters of the electron-phonon interaction were found for the cases of different values of the phonon frequencies in the barrier materials. It turned out that a significant (by almost an order of magnitude) change in the parameters of the electron-phonon interaction can occur in such structures. This makes it possible, in principle, to trace the transition from weak to strong interactions in quantum wells of the same type but with different compositions of barrier materials. The conditions are found under which an enhancement of the electron-phonon interaction is possible in an asymmetric structure in comparison with a symmetric one with the barriers of the same composition.

Binding Energies of Excitons in GaAs/AlAs Quantum Wells Under Pressure

2003 ◽  
Vol 17 (16) ◽  
pp. 863-870 ◽  
Author(s):  
Guojun Zhao ◽  
X. X. Liang ◽  
S. L. Ban
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Pressure Effect ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Longitudinal Optical ◽  
Variational Calculation ◽  
Binding Energies ◽  
Optical Phonons ◽  
Phonon Interaction

The binding energy of an exciton in the GaAs/AlAs quantum well is discussed including the influence of interface optical phonons and bulk longitudinal optical phonons confined in the well under hydrostatic pressure. The dependence of the phonon energies on pressure is considered using a linear interpolation method to obtain the pressure effect on the exciton binding energy by a variational calculation. The result shows that the polaronic effect on the exciton binding energies cannot be neglected and the pressure effect on the exciton-phonon interaction is obvious.

Nonlinear optical properties in the laser-dressed two-level AlxGa1−xN/GaN single quantum well

2018 ◽  
Vol 32 (04) ◽  
pp. 1850032 ◽  
Author(s):  
Monalisa Panda ◽  
Tapaswini Das ◽  
B. K. Panda
Keyword(s):  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
Effective Mass ◽  
Nonlinear Optical ◽  
Energy Levels ◽  
Internal Electric Field ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Increase With Increase

The electronic states in the laser-dressed hexagonal and cubic Al[Formula: see text]Ga[Formula: see text]N/GaN single quantum wells are calculated using the effective mass equation. The hexagonal single quantum well contains an internal electric field due to spontaneous and piezoelectric polarizations. The effective mass equation is solved by the finite difference method. The energy levels in both cubic and hexagonal laser-dressed wells are found to increase with increase in laser dressing as the effective well widths in both the wells increase. The intersubband energy spacing between first excited state and ground state increases in the cubic quantum well, whereas it decreases in the hexagonal well due to the presence of internal electric field in it. Using the compact density matrix method with iterative procedure, first-, second- and third-order nonlinear optical susceptibilities in the laser-dressed quantum well are calculated taking only two levels. While the susceptibilities in the hexagonal well are found to get red shifted, the susceptibilities in the cubic well are blue shifted.

Photoconductivité dans l'alliage GaAsxSb1−x en présence d'un champ magnétique

1974 ◽  
Vol 52 (8) ◽  
pp. 743-747 ◽  
Author(s):  
A. Filion ◽  
E. Fortin
Keyword(s):  
Magnetic Fields ◽  
Band Gap ◽  
Effective Mass ◽  
Alloy Composition ◽  
Longitudinal Optical ◽  
Optical Phonons ◽  
Champ Magnétique

The intrinsic photoconductivity of several samples of the alloy GaAsxSb1−x has been studied at 4.2 K in the presence of magnetic fields of up to 65 kG. Values for the band-gap, the reduced effective mass of the carriers, the energy of the longitudinal optical phonons across the alloy composition are deduced from the measurements.

Study of electron-phonon interaction in quantum wells using optically excited nonequilibrium population of phonons

1993 ◽  
Vol 13 (2) ◽  
pp. 203 ◽  
Author(s):  
Tobias Ruf ◽  
Keith Wald ◽  
Peter Y. Yu ◽  
K.T. Tsen ◽  
H. Morkoç ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Phonon Interaction ◽  
Electron Phonon Interaction
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