BINDING ENERGIES OF HYDROGENIC IMPURITIES ON-CENTER AND OFF-CENTER IN CYLINDRICAL QUANTUM DOTS UNDER ELECTRIC AND MAGNETIC FIELDS

2010 ◽  
Vol 24 (22) ◽  
pp. 4293-4304 ◽  
Author(s):  
SHENG WANG ◽  
GUOZHU WEI ◽  
GUANGYU YI
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Effective Radius ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Lateral Confinement ◽  
Electric And Magnetic Fields

The ground-state binding energies of a hydrogenic impurity in cylindrical quantum dots (QDs) subjected to external electric and magnetic fields are investigated using the finite-difference method within the quasi-one-dimensional effective potential model. The QD is modeled by superposing a square-well potential and a strong lateral confinement potential by the combination of a parabolic potential and a changeable magnetic field. We define an effective radius of a cylindrical QD which can describe the strength of the lateral confinement. The effects of the electric fields are less important when the effective radius is very tiny, and the effects are manifested as the effective radius increases. Meanwhile, one finds that the binding energies highly depend on the impurity positions under the applied transverse fields. When the impurity is located at the right half of the cylinder, the electric field pushes the electron to the left side, then the binding energy decreases; when the impurity is located at the left, the binding energy first increases and reaches a peak value, then deceases with the electric field.

PHONON CONFINEMENT EFFECT ON THE BINDING ENERGY OF A HYDROGENIC IMPURITY IN QUANTUM WIRES IN THE ELECTRIC AND MAGNETIC FIELDS

2012 ◽  
Vol 15 ◽  
pp. 184-190
Author(s):  
ABBAS SHAHBANDARI
Keyword(s):  
Binding Energy ◽  
Magnetic Fields ◽  
Quantum Wires ◽  
Polar Optical Phonon ◽  
Phonon Confinement ◽  
Hydrogenic Impurity ◽  
Bound Polaron ◽  
Electric And Magnetic Fields ◽  
Applied Fields ◽  
Variation Technique

The effect of phonon confinement on ground state binding energy of bound polaron in polar quantum wires with a finite confining potential investigated by Landau-Pekar variation technique. The effect of external electric and magnetic fields is taken into account as well. The obtained results show that the polar optical phonon confinement leads to a considerable enhancement of the polaron effect and these corrections increase with increasing of applied fields.

First-excited-state energy of hydrogenic impurity bound polaron in an anisotropic quantum dot in an electric field

2019 ◽  
Vol 33 (32) ◽  
pp. 1950386
Author(s):  
Shi-Hua Chen
Keyword(s):  
Excited State ◽  
Binding Energy ◽  
Quantum Dot ◽  
Electric Field ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Bound Polaron ◽  
First Excited State ◽  
Trial Wavefunction ◽  
Anisotropic Quantum Dot

The first-excited-state (ES) binding energy of hydrogenic impurity bound polaron in an anisotropic quantum dot (QD) is obtained by constructing a variational wavefunction under the action of a uniform external electric field. As for a comparison, the ground-state (GS) binding energy of the system is also included. We apply numerical calculations to KBr QD with stronger electron–phonon (E–P) interaction in which the new variational wavefunction is adopted. We analyzed specifically the effects of electric field and the effects of both the position of the impurity and confinement lengths in the xy-plane and the [Formula: see text] direction on the ground and the first-ES binding energies (BEs). The results show that the selected trial wavefunction in the ES is appropriate and effective for the current research system.

Viscosity of a Polar Gas of Symmetric Top Molecules in Perpendicular Electric and Magnetic Fields

1978 ◽  
Vol 33 (2) ◽  
pp. 225-227 ◽  
Author(s):  
W. E. Köhler
Keyword(s):  
Magnetic Fields ◽  
Kinetic Theory ◽  
Electric Field ◽  
Electric Fields ◽  
Pressure Difference ◽  
Viscosity Coefficients ◽  
Electric And Magnetic Fields ◽  
Symmetric Top Molecules ◽  
Field Influence

A kinetic theory treatment of the influence of perpendicular magnetic and electric fields on the viscosity is given for a polar gas of symmetric top molecules. Expressions for the 9 independent viscosity coefficients are derived. In particular, the electric field influence on the transverse viscomagnetic pressure difference is studied.

Suppression of runaway of electrons in a Lorentz plasma. II. crossed electric and magnetic fields

1970 ◽  
Vol 4 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Barbara Abraham-Shrauner
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Collision Frequency ◽  
Uniform Electric Field ◽  
Drift Motion ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

Suppression of runaway of electrons in a weak, uniform electric field in a fully ionized Lorentz plasma by crossed magnetic and electric fields is analysed. A uniform, constant magnetic field parallel to a constant or harmonically time varying electric field does not alter runaway from that in the absence of the magnetic field. For crossed, constant fields the passage to runaway or to free motion as described by constant drift motion and spiral motion about the magnetic field is lengthened in time for strong magnetic fields. The new ‘runaway’ time scale is roughly the ratio of the cyclotron frequency to the collision frequency squared for cyclotron frequencies much greater than the collision frequency. All ‘runaway’ time scales may be given approximately by t2E Teff where tE is the characteristic time of the electric field and Teff is the ffective collision time as estimated from the appropriate component of the electrical conductivity.

SPECTROSCOPY OF THE HYDROGEN AND ANTI-HYDROGEN ATOMS IN EXTERNAL FIELDS

2004 ◽  
Vol 18 (30) ◽  
pp. 3875-3886 ◽  
Author(s):  
LEONTI LABZOWSKY ◽  
VASILY SHARIPOV ◽  
DMITRI SOLOVYEV ◽  
GÜNTER PLUNIEN ◽  
GERHARD SOFF
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
External Electric Field ◽  
Electric Fields ◽  
Transition Probabilities ◽  
Cpt Violation ◽  
Hydrogen Atoms ◽  
Frequency Distributions ◽  
Electric And Magnetic Fields ◽  
Lorentz Line

The spectroscopical properties of hydrogen (H) and anti-hydrogen [Formula: see text] atoms in external electric and magnetic fields are discussed. This problem became important in connection with the recent experimental success in production of [Formula: see text] atoms. The main features of these experiments are briefly reviewed. The proposals for the search of the CPT violation via comparison of the H and [Formula: see text] spectra are shortly discussed. The spectroscopical differences between H and [Formula: see text] atoms in external magnetic fields and in parallel magnetic and electric fields are described in detail. It is proven that the positions of the maxima of the frequency distributions for transition probabilities in external electric field for H and [Formula: see text] atoms will deviate if the non-resonant corrections to the Lorentz line profile are taken into account.

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