Effect of the electron-phonon coupling on the ground state of aD−center in a spherical quantum dot

1999 ◽  
Vol 60 (23) ◽  
pp. 15558-15561 ◽  
Author(s):  
B. Szafran ◽  
B. Stébé ◽  
J. Adamowski ◽  
S. Bednarek
Keyword(s):  
Quantum Dot ◽  
Ground State ◽  
Phonon Coupling ◽  
Spherical Quantum Dot ◽  
Electron Phonon Coupling

VIBRATIONAL FREQUENCY OF IMPURITY BOUND MAGNETOPOLARON IN AN ANISOTROPIC QUANTUM DOT

2009 ◽  
Vol 23 (20n21) ◽  
pp. 2449-2456 ◽  
Author(s):  
WEI XIAO ◽  
JING-LIN XIAO
Keyword(s):  
Quantum Dot ◽  
Interaction Energy ◽  
Coupling Strength ◽  
Vibrational Frequency ◽  
Cyclotron Frequency ◽  
Operator Method ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Anisotropic Quantum Dot ◽  
Bound Magnetopolaron

We study the vibrational frequency and the interaction energy of the weak-coupling impurity bound magnetopolaron in an anisotropic quantum dot. The effects of the transverse and longitudinal effective confinement lengths, the electron–phonon coupling strength, the cyclotron frequency of a magnetic field and the Coulomb bound potential are taken into consideration by using an improved linear combination operator method. It is found that the vibrational frequency and the interaction energy will increase rapidly with decreasing confinement lengths and increasing the cyclotron frequency. The vibrational frequency is an increasing function of the Coulomb bound potential, whereas the interaction energy is an decreasing one of the potential and the electron–phonon coupling strength.

THE INFLUENCE OF ELECTRIC FIELD ON THE GROUND-STATE LIFETIME OF POLARON IN A PARABOLIC QUANTUM DOT

2011 ◽  
Vol 25 (03) ◽  
pp. 203-210
Author(s):  
WEI-PING LI ◽  
JI-WEN YIN ◽  
YI-FU YU ◽  
JING-LIN XIAO
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Phonon Coupling ◽  
Phonon Interaction ◽  
Strong Electron ◽  
Electron Phonon Interaction ◽  
Parabolic Quantum Dot

The ground-state energy of polaron was obtained with strong electron-LO-phonon coupling by using a variational method of the Pekar type in a parabolic quantum dot (QD). Quantum transition occurs in the quantum system due to the electron-phonon interaction and the influence of temperature. That is the polaron transition from the ground-state to the first-excited state after absorbing a LO-phonon and it causes the changing of the polaron lifetime. Numerical calculations are performed and the results illustrate the relations of the ground-state lifetime of the polaron on the ground-state energy of polaron, the electric field strength, the temperature, the electron-LO-phonon coupling strength and the confinement length of the quantum dot.

LATTICE DYNAMICS AND ANYON SUPERCONDUCTORS

1990 ◽  
Vol 04 (18) ◽  
pp. 1143-1151 ◽  
Author(s):  
D.M. GAITONDE ◽  
SUMATHI RAO
Keyword(s):  
Magnetic Field ◽  
Gauge Field ◽  
Spectral Function ◽  
Carrier Concentration ◽  
Ground State ◽  
Lattice Dynamics ◽  
Phonon Coupling ◽  
Dominant Effect ◽  
Electron Phonon Coupling ◽  
New Type

We consider a model of anyons—fermions coupled to a statistical gauge field—also coupled to phonons via the usual electron-phonon coupling. We study the phonon response when the system is in the superconducting anyon ground state and show the existence of peaks in the phonon spectral function whose frequencies shift with carrier concentration. We suggest that when the electron-phonon coupling is the dominant effect, there could arise a new type of BCS ground state with a spontaneously generated P and T violating supercurrent, that expels the statistical magnetic field.

Interchain Alignments and Ground State in Organic Ferromagnets

1998 ◽  
Vol 12 (28) ◽  
pp. 1167-1174
Author(s):  
W. Z. Wang ◽  
K. L. Yao ◽  
H. Q. Lin
Keyword(s):  
Spin Density ◽  
Ground State ◽  
Main Chain ◽  
Phonon Coupling ◽  
Structure Transition ◽  
Interchain Coupling ◽  
Ferromagnetic Structure ◽  
Phase Alignment ◽  
Electron Phonon Coupling ◽  
Organic Ferromagnets

Two kinds of alignments of two neighboring π-conjugated organic ferromagnetic chains are studied by considering the itinerary of electrons, electron–phonon coupling, the Hubbard repulsion and the interchain coupling. It is shown that the out-of-phase alignment is a more stable ferromagnetic structure than in-phase alignment. For out-of-phase alignment, there is a structure transition at a critical interchain coupling, at which the dimerizations of two chains have the same size and reverse sign. Interchain coupling results in transfer of spin density between each main chain and the side radicals.

Bound polaron in a narrow-band polar crystal

1993 ◽  
Vol 71 (11-12) ◽  
pp. 493-500
Author(s):  
Y. Lépine ◽  
O. Schönborn
Keyword(s):  
Effective Mass ◽  
Ground State ◽  
Narrow Band ◽  
Wave Functions ◽  
Phonon Coupling ◽  
Polar Crystal ◽  
Bound Polaron ◽  
Narrow Bandwidth ◽  
Electron Phonon Coupling ◽  
Shallow Impurities

The ground-state energy of a bound polaron in a narrow-band polar crystal (such as a metal oxide) is studied using variational wave functions. We use a Fröhlich-type Hamiltonian on which the effective mass approximation has not been effected and in which a Debye cutoff is made on the phonon wave vectors. The wave functions that are used are general enough to allow the existence of a band state and of a self-trapped state and are reliable in the nonadiabatic limit. We find that three ground states are possible for this system. First, for small electron–phonon coupling, moderate bandwidth, and shallow impurities, the usual effective-mass hydrogenic ground state is found. For a narrow bandwidth and a deep defect, a collapsed state is predicted in which the polaron coincides with the position of the defect. Finally, for moderate electron–phonon coupling, narrow bandwidth, and a very weak defect, a self-trapped polaron in a hydrogenic state is predicted. Our conclusions are presented as asymptotic expansions and as phase diagrams indicating the values of the parameters for which each phase can be found.

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