Temperature effect on first excited state energy and transition frequency of a strong-coupling polaron in a symmetry RbCl quantum dot

2014 ◽  
Vol 444 ◽  
pp. 103-105 ◽  
Author(s):  
Yong Sun ◽  
Zhao-Hua Ding ◽  
Jing-Lin Xiao
Keyword(s):  
Excited State ◽  
Quantum Dot ◽  
Temperature Effect ◽  
Strong Coupling ◽  
State Energy ◽  
Transition Frequency ◽  
Excited State Energy ◽  
First Excited State

Study of strong-coupling impurity bound polaron in a quantum pseudodot

2015 ◽  
Vol 29 (09) ◽  
pp. 1550058 ◽  
Author(s):  
R. Khordad
Keyword(s):  
Excited State ◽  
Quantum Dot ◽  
Strong Coupling ◽  
Coupling Strength ◽  
State Energy ◽  
Transition Frequency ◽  
Excited State Energy ◽  
Quantum Pseudodot ◽  
Bound Polaron ◽  
Potential Height

In the present work, we have studied the first internal excited state energy and transition frequency of strong-coupling impurity bound polaron in a quantum pseudodot using the well-known Lee–Low–Pines (LLP) unitary transformation method. We show the effect of Coulomb bound potential, electron–phonon (e–p) coupling strength, the quantum dot radius and potential height on first internal excited state energy and the transition frequency of the impurity bound polaron. According to the results, it is found that the first internal excited state energy is decreased with increasing quantum dot radius. Also, this energy is increased with enhancing potential height. The transition frequency is increased with increasing the e–p coupling strength. Also, the first internal excited state energy is increased with decreasing the e–p coupling strength. The transition frequency is enhanced with increasing the Coulomb bound potential.

Effects of Strong Coupling Magnetopolaron in Quantum Dot

1998 ◽  
Vol 12 (17) ◽  
pp. 693-701 ◽  
Author(s):  
Haiyang Zhou ◽  
Shiwei Gu ◽  
Yaoming Shi
Keyword(s):  
Excited State ◽  
Quantum Dot ◽  
Variational Method ◽  
Strong Coupling ◽  
Ground State ◽  
Cyclotron Resonance ◽  
State Energy ◽  
Two Dimensional ◽  
Excited State Energy ◽  
Limiting Case

With the use of variational method of Pekar type, we have calculated both the ground state energy and the excited state energy of strong coupling magnetopolaron in disk-shape quantum dot. The dependence of cyclotron resonance frequency of magnetopolaron on the magnetic eld and the confinement strength of quantum dot and quantum well is depicted. The limiting case of bulk type and strict two-dimensional type is discussed.

TRANSITION FREQUENCY OF WEAK-COUPLING IMPURITY BOUND MAGNETOPOLARON IN AN ANISOTROPIC QUANTUM DOT

2012 ◽  
Vol 26 (01) ◽  
pp. 1150003 ◽  
Author(s):  
CHENG-SHUN WANG ◽  
JING-LIN XIAO
Keyword(s):  
Magnetic Field ◽  
Excited State ◽  
Quantum Dot ◽  
Weak Coupling ◽  
State Energy ◽  
Cyclotron Frequency ◽  
Excited State Energy ◽  
First Excited State ◽  
Anisotropic Quantum Dot ◽  
The Magnetic Field

We study the first excited-state energy, the excitation energy and the transition frequency between the first excited- and the ground-state of weak-coupling magnetopolaron in an anisotropic quantum dot. The effects of the Coulomb bound potential, the cyclotron frequency of the magnetic field, the electron–phonon interaction and the transverse and the longitudinal effective confinement lengths are taken into account by using the linear combination operator method. It is found that studied quantities will increase with increasing Coulomb bound potential and the cyclotron frequency of the magnetic field. They are decreasing functions of the effective confinement lengths, which can be attributed to the interesting quantum size confining effect. The first excited-state energy is a decreasing function of the electron–phonon coupling strength.

TRANSITION FREQUENCY OF STRONG-COUPLING IMPURITY BOUND POLARON IN AN ASYMMETRIC QUANTUM DOT

2012 ◽  
Vol 11 (03) ◽  
pp. 1250026 ◽  
Author(s):  
CHENG-SHUN WANG ◽  
YU-FANG CHEN ◽  
JING-JIN XIAO
Keyword(s):  
Excited State ◽  
Coupling Strength ◽  
State Energy ◽  
Transition Frequency ◽  
Phonon Coupling ◽  
Excited State Energy ◽  
Bound Polaron ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum ◽  
Electron Phonon Coupling

Properties of the excited state of strong-coupling impurity bound polaron in an asymmetric quantum dot are studied by using linear combination operator and unitary transformation methods. The first internal excited state energy, the excitation energy and the transition frequency between the first internal excited and the ground states of the impurity bound polaron as functions of the transverse and the longitudinal effective confinement lengths of the dot, the electron–phonon coupling strength and the Coulomb bound potential were derived. Our numerical results show that they will increase with decreasing the effective confinement lengths, due to interesting quantum size confining effects. But they are an increasing functions of the Coulomb bound potential. The first internal excited state energy is a decreasing function of the electron–phonon coupling strength whereas the transition frequency and the excitation energy are an increasing one of the electron–phonon coupling strength.

Evaluation of AlGaAs/GaAs Heterointerface by Shubnikov-de Haas Oscillation Measurements

1986 ◽  
Vol 77 ◽  
Author(s):  
Kazumi Kasai ◽  
H. Tanaka ◽  
H. Itoh ◽  
T. Oh-Hori ◽  
M. Takikawa ◽  
...  
Keyword(s):  
Excited State ◽  
State Energy ◽  
Energy Levels ◽  
Interface Model ◽  
Dimensional Electron ◽  
Excited State Energy ◽  
Haas Oscillation ◽  
First Excited State ◽  
A New Technique

ABSTRACTThe measurement of Shubnikov-de Haas(SdH) oscillation is proposed as a new technique for evaluating the quality of a heterointerface. The first excited state of 2-dimensional electron energy levels is determined for several samples using the measurements of SdH oscillation. Lower values of the first excited state energy are found for the samples with a low mobility. The low value can be approximately explained in terms of graded interface model.

GROUND AND EXCITED STATE PHOTOLUMINESCENCE MAPPING ON InAs/InGaAs QUANTUM DOT STRUCTURES

2007 ◽  
Vol 06 (05) ◽  
pp. 383-387
Author(s):  
T. V. TORCHYNSKA ◽  
E. VELÁZQUEZ LOZADA ◽  
M. DYBIEC ◽  
S. OSTAPENKO ◽  
P. G. ELISEEV ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Dot ◽  
Excited States ◽  
Long Range ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Excited State Energy ◽  
Photoluminescence Study ◽  
Range Variation

This paper presents the photoluminescence study at 12 K and scanning photoluminescence spectroscopy investigation of the ground and excited states at 80 and 300 K on InAs QDs inserted in In 0.15 Ga 0.85 As / GaAs QW structures and created at different QD growth temperatures. It is shown that investigated structures are characterized by the long range variation of an average QD size in QD ensemble across the wafer. This long range QD size inhomogeneity was used for investigation of the multi-excited state energy trend versus ground state energy (or QD sizes).

Nonlinear absorption coefficient and refractive index changes of two-dimensional two-electron quantum dot in rigid confinement

2019 ◽  
Vol 33 (09) ◽  
pp. 1950078
Author(s):  
Menberu Mengesha Woldemariam
Keyword(s):  
Refractive Index ◽  
Excited State ◽  
Quantum Dot ◽  
Absorption Coefficient ◽  
Ground State ◽  
State Energy ◽  
Two Dimensional ◽  
First Excited State ◽  
Trial Wavefunction ◽  
Index Changes

The Hamiltonian and wavefunctions describing two-dimensional (2D) two-electron ZnO quantum dot in rigid confinement are developed. Then the Schrödinger equation is solved analytically and numerically for determining the ground and excited state energies. The ground state energy of 2D two-electron ZnO quantum dot (QD) in rigid confinement is studied using perturbation and variational methods. The obtained result show that our trial wavefunction is good enough to describe the 2D two-electron QD in rigid confinement. The wavefunction describing the ground state is the combination of symmetric spatial wavefunction and antisymmetric spin wavefunction which is a para-state. The ground state energy eigenvalue obtained by variational technique is a little above that of a perturbation technique. Based on this; the trial wavefunction for the excited state is developed. The excited state energy of 2D two-electron ZnO QD in rigid confinement is studied computationally using variational method. The wavefunction describing the excited state is the combination of symmetric spatial wavefunction with antisymmetric spin wavefunction (para-state) or vice versa (ortho-state). The para and ortho-state energies of the first excited state are calculated and their difference is twice of the exchange energy. Based on the obtained energy eigenvalues of the ground and the first excited state at the value of the coupling constant [Formula: see text] [Formula: see text] 1, the third-order nonlinear absorption coefficient and refractive index changes are investigated. The optical transition is only considered between the two lowest para states.

Sign in / Sign up

Export Citation Format

Share Document