Influence Of Electron-electron Interaction Research Articles

The Influence of Electron-Electron Interaction on RKKY Magnetic Coupling between Local Spins of Diluted Magnetic Semiconductor Quantum Dots

Regulated magnetic interactions in semiconductor nanometer structure have a strong application background in spin electronics and quantum information processing. This paper mainly studies the influence of electron interaction on the magnetic coupling between diluted magnetic semiconductor quantum dots embedded in semiconductors. Taking into account the interaction between electrons, we will calculate the RKKY Magnetic interaction between the local spins of two diluted magnetic semiconductor quantum dots embedded in the semiconductor applying the Keldysh Green’s function method. For the electronic interaction, we use the simple self-consistent mean-field approximation.

Phonon drag thermoelectric phenomena in mesoscopic two-dimensional conductors: Current stripes, large Nernst effect, and influence of electron-electron interaction

The interaction of electrons with a flux of ballistic phonons leads to excitation of many angular harmonics of an electron distribution function. We show that this property dramatically modifies the magnetothermoelectric phenomena in two-dimensional electron systems with boundaries. By considering classical magnetotransport of electrons in a narrow channel with partly diffusive boundary scattering, we show that the phonon flux excites a pattern of current stripes with alternating directions of propagation along the channel. The Nernst voltage due to phonon drag appears already in the classical transport regime and can be comparable with the Seebeck voltage, while the latter acquires a dependence on the magnetic field. The temperature dependence of these voltages shows an unusual behavior determined by relaxation of higher-order harmonics of the distribution function via electron-electron scattering. Our experimental studies of mesoscopic samples based on high-quality GaAs quantum wells confirm the main properties of the thermoelectric response suggested by the theory.

Two-dimensional weak anti-localization in Bi2Te3 thin film grown on Si(111)-(7 × 7) surface by molecular beam epitaxy

We report on low temperature transport studies of Bi2Te3 topological insulator thin films grown on Si(111)-(7 × 7) surface by molecular beam epitaxy. A sharp increase in the magnetoresistance with magnetic field at low temperature indicates the existence of weak anti-localization. The measured weak anti-localization effect agrees well with the Hikami-Larkin-Nagaoka model, and the extracted phase coherence length shows a power-law dependence with temperature indicating the existence of a two-dimensional system. An insulating ground state has also been observed at low temperature showing a logarithmic divergence of the resistance that appears to be the influence of electron-electron interaction in a two-dimensional system.

Effect of the emitter spacer level on the peak current of resonant tunneling diode

The dependence of the peak current in the I–V characteristic of a resonant tunneling diode on the emitter spacer thickness has been investigated by numerically solving the Schrodinger equation. This dependence has pronounced maxima in which the peak current greatly exceeds that in minima. The mechanism of the formation of maxima has been revealed. These maxima are caused by the overlap of the emitter spacer level and the resonant level of the quantum well. The influence of electron-electron interaction on the effect has been studied; it is shown that the interaction barely affects the peak current in the forward bias direction and somewhat decreases it in the reverse direction.

Influence of electron-electron interaction on the cyclotron resonance spectrum of magnetic quantum dots containing few electrons

The configuration interaction method is used to obtain the magneto-optical absorption spectrum of a few-electron (${N}_{e}=1,2,\dots{},5$) quantum dot containing a single magnetic ion. We find that the IR spectrum (the position, the number, and the oscillator strength of the cyclotron resonance peaks) depends on the strength of the Coulomb interaction, the number of electrons, and the position of the magnetic ion. We find that the Kohn theorem is no longer valid as a consequence of the electron-spin-magnetic-ion-spin-exchange interaction.

An Analytical Approach to Thermal and Electrical Transport in aMesoscopic Conductor**The project supported in partby National Natural Science Foundation of China under Grant No. 10404037

In order to consider the thermal and electrical coherent transport in amesoscopic conductor under the influence of electron-electron interaction,in this paper, we establish a method in terms of which one can analyticallyobtain the Hartree self-consistent potential instead of computing it by thenumerical iterative procedure as usual, which is convenient for us todescribe the thermal and electric current flow through a mesoscopicconductor. If we study the electron-electron interaction at the Hartreeapproximation level, the Hartree potential satisfies the Poisson equationand Schrödinger equation, so when we expand the action function S(x)by Planck constant ℏ, the self-consistent potential and thewavefunction can be solved analytically order by order, and the thermal andelectrical conductance can thus be obtained readily. However, we just showthe quantum corrections up to the second order.

Electron-Electron Interaction Effect on the Conformational Soliton of Deoxyribonucleic Acid

The local conformational behavior of deoxyribonucleic acid (DNA) has been discussed by considering the electron-electron interaction. We set up the coupled nonlinear equations to describe the interaction between the longitudinal displacement of DNA backbone and the electronic wave function. Under the case of approximated condition, we obtain the analytic solution of the electronic wave function and longitudinal displacement. The influence of electron-electron interaction upon the parameters of conformational soliton such as the amplitude and width have been revaluated. With the increasing of electron-electron interaction, the amplitude and half-width will increase.

Influence of electron-electron interaction on the vibrational frequency in one-dimensional dimerized conjugated systems.

We apply the correlated-basis-function approach to study the vibrational stretching mode in a one-dimensional dimerized conjugated system modeled as a Kronig-Penney square-well lattice. Poly- acetylene is taken as prototypical example. Various potential parameters are considered in the one-dimensional energy-band calculations. We find that the one-electron theory is unable to afford simultaneously reasonable descriptions of the electronic and vibrational properties, which indicates the importance of electron-electron interaction in the vibrational modes (and lattice relaxation). Our parameters are selected according to the ionization potential value in polyacetylene. Electron-electron interaction is taken as a screened Coulomb potential. The correlated wave function is evaluated through the Chakravarty-Woo equation within the convolution approximation. We find that electron-electron interaction generally increases the stretching-mode frequency; however, in systems with very large spring constants, the vibrational frequency first decreases as the electron-electron interaction strength increases, then levels off and begins to increase.

Ladder-like conjugated polymers

As a consequence of the Peierls instability single-chain conjugated polymers show an energy gap. Metallic properties are obtained only by closing the gap via doping the polymer. One-electron models indicate ways of reducing or avoiding the gap at all by coupling two or more chains together. The influence of electron-electron interaction is estimated by means of approximations beyond mean field theory. A comparison with observed real structure is given.

Perpendicular upper critical field of layered superconductor

The influence of electron-electron interaction on perpendicular upper critical field of layered superconductor is studied theoretically. It is shown that the upward curvature in HC2(T) is possible.

The influence of electron-electron interaction on the temperature dependence of the magnon damping in disordered ferromagnetic metals

The temperature dependent part of magnon damping in disordered ferromagnetic metals is investigated within the framework of the spin operator diagram technique. The interference between the magnon electron interaction and the Coulomb one as well as the electron-impurity rescattering are considered. The calculations shows, that the contribution to the magnon relaxation rate due to this interference mechanism is of the hydrodynamic type γ k ∼ k zω k which depends on temperature as √ T for d=3, log( T) for d=2 and 1/√ T for d=1 ( d is the space dimensionality).

Influence of electron-electron interaction on hopping conduction of disordered systems

Influence of electron-electron interaction on hopping conduction of disordered systems

The influence of electron-electron interaction on inner-shell excitation processes in heavy-ion collisions

The authors present calculations of electron excitation rates in heavy-ion collisions, in which the electron-electron interaction is treated within a relativistic self-consistent field approach. In comparison with earlier calculations neglecting electron shielding, the authors obtain increased probabilities for K-hole and delta -electron production, whereas the total positron yield decreases. Computed probabilities are compared with available experimental data.