scholarly journals Screened interaction and self-energy in an infinitesimally polarized electron gas via the Kukkonen-Overhauser method

2000 ◽  
Vol 61 (19) ◽  
pp. 12556-12559 ◽  
Author(s):  
Sudhakar Yarlagadda ◽  
Gabriele F. Giuliani
Keyword(s):  
Electron Gas ◽  
Self Energy

Electron-gas self-energy at metallic density

1988 ◽  
Vol 38 (6) ◽  
pp. 3834-3840 ◽  
Author(s):  
C. Petrillo ◽  
F. Sacchetti
Keyword(s):  
Electron Gas ◽  
Self Energy

RENORMALIZATION OF FERMI VELOCITY IN A COMPOSITE TWO DIMENSIONAL ELECTRON GAS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 87-94 ◽  
Author(s):  
M. WEGER ◽  
L. BURLACHKOV
Keyword(s):  
Electron Gas ◽  
Fermi Velocity ◽  
Bohr Radius ◽  
Dimensional Electron ◽  
Temperature Dependent ◽  
Two Dimensional Electron Gas ◽  
Self Energy ◽  
2D System ◽  
Dimensional Electron Gas ◽  
The One

We calculate the self-energy Σ(k, ω) of an electron gas with a Coulomb interaction in a composite 2D system, consisting of metallic layers of thickness d ≳ a 0, where a 0 = ħ2∊1/ me 2 is the Bohr radius, separated by layers with a dielectric constant ∊2 and a lattice constant c perpendicular to the planes. The behavior of the electron gas is determined by the dimensionless parameters k F a 0 and k F c ∊2/∊1. We find that when ∊2/∊1 is large (≈5 or more), the velocity v(k) becomes strongly k-dependent near k F , and v ( k F ) is enhanced by a factor of 5-10. This behavior is similar to the one found by Lindhard in 1954 for an unscreened electron gas; however here we take screening into account. The peak in v(k) is very sharp (δ k/k F is a few percent) and becomes sharper as ∊2/∊1 increases. This velocity renormalization has dramatic effects on the transport properties; the conductivity at low T increases like the square of the velocity renormalization and the resistivity due to elastic scattering becomes temperature dependent, increasing approximately linearly with T. For scattering by phonons, ρ ∝ T 2. Preliminary measurements suggest an increase in v k in YBCO very close to k F .

Electron self-energy, effective mass and lifetime in a layered electron gas

1988 ◽  
Vol 196 (1-3) ◽  
pp. 482-486 ◽  
Author(s):  
P. Hawrylak ◽  
G. Eliasson ◽  
J.J. Quinn
Keyword(s):  
Effective Mass ◽  
Electron Gas ◽  
Self Energy

THE SCREENING FUNCTION OF AN INTERACTING ELECTRON GAS

1966 ◽  
Vol 44 (9) ◽  
pp. 2137-2171 ◽  
Author(s):  
D. J. W. Geldart ◽  
S. H. Vosko
Keyword(s):  
Electron Gas ◽  
Substantial Contribution ◽  
Fundamental Relation ◽  
Many Body ◽  
Screening Constant ◽  
Self Energy ◽  
Self Consistent ◽  
Small Wave ◽  
Many Body Perturbation Theory ◽  
Zero Frequency

The screening function of an interacting electron gas at high and metallic densities is investigated by many-body perturbation theory. The analysis is guided by a fundamental relation between the compressibility of the system and the zero-frequency small wave-vector screening function (i.e. screening constant). It is shown that the contribution from a graph not included in previous work is essential to obtain the lowest-order correlation correction to the screening constant at high density. Also, this graph gives a substantial contribution to the screening constant at metallic densities. The general problem of choosing a self-consistent set of graphs for calculating the screening function is discussed in terms of a coupled set of integral equations for the propagator, the self-energy, the vertex function, and the screening function. A modification of Hubbard's (1957) form of the screening function is put forward on the basis of these results.

Influence of Electron-Electron Correlations and Lattice Effects on Positron-Electron Enhancement Factors

2010 ◽  
Vol 666 ◽  
pp. 5-9 ◽  
Author(s):  
Edward Boroński
Keyword(s):  
Electron Gas ◽  
Momentum Density ◽  
Many Body ◽  
Fermi Sphere ◽  
Self Energy ◽  
Density Distributions ◽  
Lattice Effects ◽  
Electron Positron ◽  
Enhancement Factors ◽  
Momentum Distributions

We present an approach taking into account the effect of electron-electron (e-e) correlations on electron-positron (e-p) momentum density distributions. The approach bases on the modification of the Bethe-Goldstone (B-G) equation for the positron in the electron gas due to self-energy effects. The example calculations have been performed for selected parameters corresponding to simple metals. The calculated dependencies exhibit the increase of the e-p enhancement factors below Fermi momentum, like Kahana enhancements, and a decrease above the Fermi sphere, leading to a many-body “tail” in the e-p momentum density distributions. Moreover, the influence of lattice effects on enhancement factors (EF) is taken into account. This decreases by a few percent the absolute values of the e-p momentum distributions and the corresponding annihilation rates and for real metals such as Mg or Cu evidently improve the agreement with experiment.

Über den Zusammenhang zwischen Selbstenergiefunktional und Ansprechfunktion eines wechselwirkenden Elektronengases

1969 ◽  
Vol 24 (12) ◽  
pp. 1871-1878
Author(s):  
W Kessel
Keyword(s):  
Integral Equation ◽  
Force Field ◽  
Response Function ◽  
Linear Functional ◽  
Electron Gas ◽  
Dyson Equation ◽  
Energy Functional ◽  
The Self ◽  
Applied Force ◽  
Self Energy

AbstractBy linearizing the Dyson equation of the electron gas in an externally applied force field an integral equation for the adiabatic response function is derived. Its relation to the electron self-energy is considered which leads to certain approximations in the response function if the self-energy functional is given. This is illustrated for the case that the self-energy is a linear functional of the electron Green's function.

EXCHANGE CORRECTIONS AND THE CONVERGENCE OF THE PERTURBATION EXPANSION FOR THE MOMENTUM DISTRIBUTION FUNCTION FOR AN INTERACTING ELECTRON GAS AT METALLIC DENSITIES

1964 ◽  
Vol 42 (10) ◽  
pp. 1938-1968 ◽  
Author(s):  
D. J. W. Geldart ◽  
A. Houghton ◽  
S. H. Vosko
Keyword(s):  
Momentum Distribution ◽  
Random Phase ◽  
Electron Gas ◽  
Perturbation Expansion ◽  
Computational Techniques ◽  
Order Effects ◽  
Self Energy ◽  
Momentum Distribution Function ◽  
Theory Approximation ◽  
Higher Order Effects

The ground-state momentum distribution of an interacting electron gas at metallic densities is investigated by means of many-particle perturbation theory. Approximation methods and computational techniques are developed for the evaluation of the leading exchange corrections to the Random Phase Approximation. It is concluded that the straightforward perturbation expansion, which includes only single direct and exchange self-energy insertions, does not converge at the lower metallic densities and that it is necessary to include "higher-order" effects by renormalizing the electron propagator. When this is done, a large gap at the Fermi surface remains in the momentum distribution even for rs ~ 6.

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