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.

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.

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.

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.

Influence of Rashba spin-orbit interaction and Zeeman splitting on the ground state energy of polaron in an asymmetric quantum dot

2015 ◽  
Vol 29 (22) ◽  
pp. 1550124 ◽  
Author(s):  
Zhi-Xin Li ◽  
Cheng-Hong Yin ◽  
Xiu-Yun Zhu
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Zeeman Splitting ◽  
Coupling Energy ◽  
Asymmetric Quantum Dot ◽  
Rashba Spin ◽  
Asymmetric Quantum ◽  
Splitting Energy ◽  
The Absolute

On the basis of Lee–Low–Pines unitary transformation, the influence of Rashba spin-orbit (RSO) interaction and Zeeman splitting on the ground state energy of polaron in an asymmetric quantum dot (AQD) is studied by using the variational method of Pekar type. The variations of the absolute ratios of the Zeeman splitting energy and the RSO coupling energy to the ground state energy of polaron with the transverse confinement length (TCL) and the longitudinal confinement length (LCL) of AQD and the magnetic field adjusting length (MFAL) are derived when the RSO interaction and the Zeeman splitting are taken into account. We find the influences of the Zeeman splitting energy and the RSO coupling energy on the ground state energy of a polaron are more dominant when the values of the TCL and the LCL are small. The absolute ratio of the Zeeman splitting energy to the ground state energy rapidly decreases with increasing the MFAL and the absolute ratio of the RSO coupling energy to the ground state energy slowly decreases with increase in MFAL when [Formula: see text], whereas the absolute ratio of the RSO coupling energy to the ground state energy rapidly increases with increase in MFAL when [Formula: see text]. The above results can be attributed to the interesting quantum size confining and spin effects.

POLARON IN A QUANTUM DOT UNDER AN ELECTRIC FIELD

2007 ◽  
Vol 21 (24) ◽  
pp. 1635-1642
Author(s):  
MIAN LIU ◽  
WENDONG MA ◽  
ZIJUN LI
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Field Intensity ◽  
Ground State Energy ◽  
Ground State ◽  
Electric Field Intensity ◽  
State Energy ◽  
Theoretical Study ◽  
The Moment ◽  
Transformation Methods

We conducted a theoretical study on the properties of a polaron with electron-LO phonon strong-coupling in a cylindrical quantum dot under an electric field using linear combination operator and unitary transformation methods. The changing relations between the ground state energy of the polaron in the quantum dot and the electric field intensity, restricted intensity, and cylindrical height were derived. The numerical results show that the polar of the quantum dot is enlarged with increasing restricted intensity and decreasing cylindrical height, and with cylindrical height at 0 ~ 5 nm , the polar of the quantum dot is strongest. The ground state energy decreases with increasing electric field intensity, and at the moment of just adding electric field, quantum polarization is strongest.

Effects of a scattering center on the ground-state energy of quantum-dot lithium

2017 ◽  
Vol 31 (07) ◽  
pp. 1750071
Author(s):  
Z. D. Vatansever ◽  
S. Sakiroglu ◽  
I. Sokmen
Keyword(s):  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Electronic Charge ◽  
Strongly Correlated ◽  
Configuration Interaction Method ◽  
Charge Localization ◽  
Scattering Center ◽  
Spin Properties

In this paper, the effects of a repulsive scattering center on the ground-state energy and spin properties of a three-electron parabolic quantum dot are investigated theoretically by means of configuration interaction method. Phase transition from a weakly correlated regime to a strongly correlated regime is examined from several strengths and positions of Gaussian impurity. Numerical results reveal that the transition from spin-1/2 to spin-3/2 state depends strongly on the location of the impurity which accordingly states the controllability of the spin polarization. Moreover, broken circular symmetry results in more pronounced electronic charge localization.

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.

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