Electron–optical-phonon interaction in quantum wells consisting of mixed crystals

1999 ◽  
Vol 60 (7) ◽  
pp. 4937-4943 ◽  
Author(s):  
Ruisheng Zheng ◽  
Mitsuru Matsuura
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Mixed Crystals ◽  
Phonon Interaction

DEPENDENCE OF EXCITON FORMATION ON ITS CENTER-OF-MASS MOMENTUM IN QUANTUM WELLS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3660-3663 ◽  
Author(s):  
I.-K. OH ◽  
JAI SINGH
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Acoustic Phonon ◽  
Center Of Mass ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Deformation Potential ◽  
Phonon Interaction ◽  
Carrier Temperature ◽  
Comprehensive Study

We present a comprehensive study of the process of exciton formation due to exciton-phonon interaction. Using the exciton-phonon interaction arising from deformation potential, piezoelectric, and polar couplings, we have calculated the rate of formation of an exciton as a function of carrier densitiies, temperatures, and center-of-mass momentum ( K ‖) in quantum wells. Our results show that excitons are dominantly formed at non-zero K ‖, which agrees very well with experiments. The formation of an exciton due to emission of longitudinal optical phonon is found to be more efficient at relatively small values of K ‖, and that due to acoustic phonon emission is more efficient at relatively large K ‖ values for carrier temperature Te-h≲50 K.

Electron–Interface–Phonon Interaction and Magnetopolaronic Impurity Transitions in Quantum Wells

1997 ◽  
Vol 11 (08) ◽  
pp. 991-1008 ◽  
Author(s):  
R. Chen ◽  
D. L. Lin
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Phonon Frequency ◽  
Transition Energy ◽  
Bulk Sample ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Phonon Interaction ◽  
Double Heterostructure

The polaronic effect on the hydrogenic 1s–2p+ transition energy of a donor impurity located at the quantum well center in a double heterostructure is studied theoretically in detail. The electron–optical–phonon interaction Hamiltonian is derived on the basis of eigenmodes of lattice vibrations supported by the double heterostructure. Both the confined and interface phonon modes are included in the electron–phonon coupling. The transition energy is calculated as a function of the applied magnetic field for GaAs/Al 1-x Ga x As samples of well -widths d=125 Å, 210 Å and 450 Å by the second-order perturbation. Wide transition gaps are predicted around the two-level and three-level resonances for all three cases. It is found that the transition gap narrows with the increasing well-width but remains larger than the LO and TO phonon frequency difference for d=450 Å as is observed. We also perform the same calculation by assuming that the confined electron interacts with three-dimensional and two-dimensional phonon modes. The transition energy spectra from these calculations appear to be similar to those for a bulk sample, the spectrum splits at the resonance with the longitudinal optical phonon frequency only. From comparisons of our results with these calculations as well as with experiments, it is conclusively established that the wide gap of transition energy is solely due to the interface modes.

DISPERSIONS AND FRÖHLICH ELECTRON–PHONON INTERACTION HAMILTONIAN OF PROPAGATING OPTICAL PHONON MODES IN QUASI-ONE-DIMENSIONAL WURTZITEGaN-BASED QUANTUM WELL WIRES

2007 ◽  
Vol 14 (05) ◽  
pp. 903-910 ◽  
Author(s):  
L. ZHANG ◽  
HONG-JING XIE
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optical Phonon ◽  
Detailed Comparison ◽  
Continuous Functions ◽  
Uniaxial Crystal ◽  
Phonon Modes ◽  
Phonon Interaction ◽  
One Dimensional ◽  
Quantum Well Wire

Based on the dielectric continuum model and Loudon's uniaxial crystal model, the propagating (PR) optical phonon modes and the Fröhlich-like electron–PR phonon interaction Hamiltonian in a quasi-one-dimensional (Q1D) wurtzite quantum well wire (QWW) structure are deduced and analyzed. Numerical calculations on AlGaN / GaN / AlGaN wurtzite QWW are performed. Results reveal that the dispersive frequencies of PR modes are the continuous functions of free wavenumber kzin z-direction and discrete functions of azimuthal quantum number m. The reduced behavior of the PR modes in wurtzite quantum systems is obviously observed. From the discussion of the electron–PR phonon coupling functions, it is found that the low-order PR modes in the case of small kzand m play a more important role in the electron–PR phonon interactions. Moreover, a detailed comparison of the PR modes in Q1D QWW structures with those in quasi-two-dimensional quantum wells are also carried out. The physical reasons resulting in the relationship and distinction in the two types of systems are also analyzed deeply.

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