INFLUENCE OF LATTICE VIBRATION ON THE GROUND STATE OF MAGNETOPOLARON IN A PARABOLIC QUANTUM DOT

2010 ◽  
Vol 24 (27) ◽  
pp. 2705-2712 ◽  
Author(s):  
EERDUNCHAOLU ◽  
WEI XIN ◽  
YUWEI ZHAO
Keyword(s):  
Magnetic Field ◽  
Strong Coupling ◽  
Ground State Energy ◽  
Vibration Frequency ◽  
Ground State ◽  
Weak Coupling ◽  
State Energy ◽  
Cyclotron Frequency ◽  
Lattice Vibration ◽  
The Magnetic Field

Influence of the lattice vibration on the properties of the magnetopolaron in the parabolic quantum dots (QDs) is studied by using the Huybrechts' linear combination operator and Lee–Low–Pines (LLP) transformation methods. The expressions for the vibration frequency and the ground-state energy of the magnetopolaron as functions of the confinement strength of the QDs, the magnetic field and temperature are derived under the strong and weak coupling, respectively. The results of the numerical calculations show that the changes of the vibration frequency and ground-state energy of the magnetopolaron with the confinement strength of the QDs, the magnetic field and temperature are different under different couplings. The vibration frequency and the ground-state energy of the weak-coupling magnetopolaron and the vibration frequency of the strong-coupling magnetopolaron will increase with increase of the confinement strength of the QDs and cyclotron frequency, the vibration frequency and ground-state energy of the strong-coupling magnetopolaron. However, the ground-state energy of the weak-coupling magnetopolaron will decrease with increase of the temperature. The dependence of the ground-state energy of the strong-coupling magnetopolaron on the confinement strength of the QDs and cyclotron frequency is strongly influenced by the temperature. The remarkable influence of the temperature on the ground-state energy of the magnetopolaron arises when the temperature is relatively higher.

The effect of temperature on strong-coupling magnetopolaron in an asymmetrical Gaussian potential quantum well

2020 ◽  
Vol 34 (12) ◽  
pp. 2050114
Author(s):  
Xiu-Juan Miao ◽  
Yong Sun ◽  
Jing-Lin Xiao
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Strong Coupling ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Cyclotron Frequency ◽  
Operator Method ◽  
Effect Of Temperature ◽  
Gaussian Potential

The influences of temperature and cyclotron frequency of a magnetic field on the ground state energy and mean number of phonons (MNP) of strong-coupling magnetopolarons in an asymmetric Gaussian potential quantum well(AGPQW) are researched by employing the linear-combination operator method and the unitary transformation. It was demonstrated through the numerical calculations that the ground state energy and the MNP increase with higher magnetic field cyclotron frequencies and temperature. In addition, increasing of the barrier of asymmetric Gaussian potential (AGP) causes the ground state energy to decrease while increasing the MNP of magnetopolarons.

The influences of parabolic potential and magnetism on strongly coupled polaron characteristics within asymmetric Gaussian quantum wells

2021 ◽  
Author(s):  
Saren Gaowa ◽  
Yan-Bo Geng ◽  
Zhao-Hua Ding ◽  
Jing-Lin Xiao
Keyword(s):  
Magnetic Field ◽  
Quantum Wells ◽  
Barrier Height ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Cyclotron Frequency ◽  
Strongly Coupled ◽  
Parabolic Potential ◽  
Do So

In this research, the effects of magnetism and parabolic potential on strongly coupled polaron characteristics within asymmetric Gaussian quantum wells (AGQWs) were investigated. To do so, the following six parameters were studied, temperature, AGQW barrier height, Gaussian confinement potential (GCP) width, confinement strengths along the directions of [Formula: see text] and [Formula: see text], as well as magnetic field cyclotron frequency. The relationships among frequency oscillation, AGQW parameters and polaron ground state energy in RbCl crystal were studied based on linear combination operator and Lee–Low–Pines unitary transformation. It was concluded that ground state energy absolute value was decreased by increasing GCP width and temperature, and increased with the increase of confinement strength along [Formula: see text] and [Formula: see text] directions, cyclotron frequency of magnetic field and barrier height of AGQW. It was also found that vibrational frequency was increased by enhancing confinement strengths along the directions of [Formula: see text] and [Formula: see text], magnetic field cyclotron frequencies, barrier height AGQW and temperature and decreased with the increase of GCP width.

GROUND STATE ENERGIES OF HYDROGEN-LIKE IMPURITY IN A LENS-SHAPED QD

2004 ◽  
Vol 18 (17n19) ◽  
pp. 2529-2533 ◽  
Author(s):  
XIANGHUA ZENG ◽  
JIAFENG CHANG ◽  
PENGXIA ZHOU
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Lateral Deviation ◽  
Mass Approximation ◽  
The Magnetic Field ◽  
Ground State Energies ◽  
Electronic Ground

In this paper,the ground state energies of hydrogen-like impurity in a lens-shaped quantum dot ( GaAs / In 1-x Ga x As ) under vertical magnetic field have been discussed by using effective mass approximation and variational method. It gives that for a lens-shaped quantum dot, due to the asymmetry of the vertical and lateral bound potentials, the electronic ground state energies are related not only with the deviation distance but also with the deviation direction; for the spherical quantum dot, the ground state energy is only related with the distance of the impurity deviation, neither with vertical nor lateral deviation. And with the increasing of the magnetic field, the ground state energy is increasing.

Research on Information Applied Technology in the Study of Two-Layer Quantum Dots System

2013 ◽  
Vol 473 ◽  
pp. 133-136
Author(s):  
An Mei Wang
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Ground State ◽  
Weak Coupling ◽  
State Energy ◽  
Electron System ◽  
Exact Diagonalization ◽  
Hamiltonian Matrix ◽  
Applied Technology ◽  
The Magnetic Field

We study a two-electron system in a double-layer quantum dot under a magnetic field by means of the exact diagonalization of the Hamiltonian matrix. We find that discontinuous ground-state energy transitions are induced by an external magnetic field in the case of strong coupling. However, in the case of weak coupling, the angular momentum of the true ground state does not change in accordance with the change of the magnetic field B and remains = 0.

CONTINUOUS UPPER BOUND ON THE GROUND-STATE ENERGY OF THE FRÖHLICH POLARON

1994 ◽  
Vol 08 (08n09) ◽  
pp. 553-560 ◽  
Author(s):  
A. V. SOLDATOV
Keyword(s):  
Magnetic Field ◽  
Asymptotic Behavior ◽  
Ground State Energy ◽  
Upper Bound ◽  
Ground State ◽  
Coherent States ◽  
Weak Coupling ◽  
State Energy ◽  
Coupling Parameter ◽  
Weak Coupling Limit

The upper bound on the ground-state energy for the Fröhlich polaron is derived by means of a new version of variational principle based on the Wick symbols formalism and the coherent states theory. The bound is continuous in some respect, i.e. it is valid for all values of coupling parameter including the intermediate regions. Asymptotic behavior of the bound for the weak coupling limit and for the strong coupling limit provides, in general, lower values than well-known existing bounds. The bound can be readily generalized for the case of nonzero magnetic field.

EFFECTS OF SPIN ON THE GROUND-STATE ENERGY OF STRONG-COUPLED BOUND MAGNETOPOLARON IN AN ASYMMETRIC QUANTUM DOT

2012 ◽  
Vol 26 (30) ◽  
pp. 1250185 ◽  
Author(s):  
ZHI-XIN LI ◽  
JING-LIN XIAO
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Coupled Model ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum ◽  
The Magnetic Field ◽  
Bound Magnetopolaron

The properties of a strong-coupled bound magnetopolaron in an asymmetric quantum dot (QD) have been investigated by using the Tokuda modified linear combination operator and the unitary transformation methods on the basis of the Huybrechts' strong-coupled model. We derive the expressions of the ground-state energy as function of the transverse and longitudinal confinement lengths, the magnetic field. Numerical calculation is performed and the results show that the ground-state energy of the bound magnetopolaron splits into two branches, taking into account the spin influences. And the ground-state energy decreases with increasing the transverse and longitudinal confinement lengths and increases with the rising of the magnetic field.

GROUND STATE LIFETIME OF STRONG-COUPLING MAGNETOPOLARON IN AN ASYMMETRIC QUANTUM DOT

2009 ◽  
Vol 23 (12) ◽  
pp. 1547-1555 ◽  
Author(s):  
ZHIXIN LI ◽  
JINGLIN XIAO
Keyword(s):  
Quantum Dot ◽  
Strong Coupling ◽  
Ground State Energy ◽  
Vibration Frequency ◽  
Ground State ◽  
Coupling Strength ◽  
State Energy ◽  
External Temperature ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum

The ground state lifetime of a magnetopolaron was investigated with electron–LO-phonon strong coupling in an asymmetric quantum dot using the linear combination operator and unitary transformation methods. Quantum transition, which cause changes of the magnetopolaron lifetime, occurs in the quantum system due to electron–phonon interaction and the influence of external temperature, that is, the magnetopolaron leaps from the ground state to the first excited state after absorbing a LO-phonon. The expressions of the ground state lifetime of the magnetopolaron as a function of the ground state energy, the transverse and longitudinal confinement lengths of quantum dot, the electron–phonon coupling strength, the cyclotron vibration frequency and the external temperature were obtained. Numerical calculations have been performed and the results show that the ground state lifetime of the magnetopolaron increases with increasing the ground state energy and the cyclotron vibration frequency, and decreases with increasing the transverse and longitudinal confinement lengths of the quantum dot, the coupling strength and the external temperature.

Influence of magnetic field on the properties of polaron in an asymmetric quantum dot

2019 ◽  
Vol 33 (23) ◽  
pp. 1950263
Author(s):  
Shu-Ping Shan ◽  
Shi-Hua Chen ◽  
Ren-Zhong Zhuang ◽  
Chun Hu
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Variation Method ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum ◽  
Inversion Asymmetry ◽  
The Magnetic Field

Influence of the magnetic field on the properties of the polaron in an asymmetric quantum dot is studied by using the Pekar variation method. The expression of the magnetopolaron ground-state energy is obtained by theoretical derivation. The relationship between the ground-state energy of the magnetopolaron with the transverse confinement strength, the longitudinal confinement strength and the magnetic field cyclotron resonance frequency are further discussed by us. Due to the crystal structure inversion asymmetry and the time inversion asymmetry, the polaron energy causes Rashba spin–orbit splitting and Zeeman splitting. Under the strong and weak magnetic fields, we discuss the dominant position of Rashba effect and Zeeman effect, respectively. Due to the presence of phonons, the polaron is more stable than the bare electron state, and the energy splitting is more stable.

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.

TIGHT-BINDING MODEL FOR THE QUANTUM LADDER IN A MAGNETIC FIELD

1996 ◽  
Vol 10 (28) ◽  
pp. 3827-3856 ◽  
Author(s):  
KAZUMOTO IGUCHI
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Tight Binding ◽  
Critical Value ◽  
Tight Binding Model ◽  
Binding Model ◽  
First Case

A tight-binding model is formulated for the calculation of the electronic structure and the ground state energy of the quantum ladder under a magnetic field, where the magnetic flux at the nth plaquette is given by ϕn. First, the theory is applied to obtain the electronic spectra of the quantum ladder models with particular magnetic fluxes such as uniform magnetic fluxes, ϕn=0 and 1/2, and the staggered magnetic flux, ϕn= (−1)n+1ϕ0. From these, it is found that as the effect of electron hopping between two chains—the anisotropy parameter r=ty/tx—is increased, there are a metal-semimetal transition at r=0 and a semimetal–semiconductor transition at r=2 in the first case, and metal-semiconductor transitions at r=0 in the second and third cases. These transitions are thought of as a new category of metal-insulator transition due to the hopping anisotropy of the system. Second, using the spectrum, the ground state energy is calculated in terms of the parameter r. It is found that the ground state energy in the first case diverges as r becomes arbitrarily large, while that in the second and third cases can have the single or double well structure with respect to r, where the system is stable at some critical value of r=rc and the transition between the single and double well structures is associated with whether tx is less than a critical value of txc. The latter cases are very reminiscent of physics in polyacetylene studied by Su, Schrieffer and Heeger.

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