scholarly journals Metal surface energy: Persistent cancellation of short-range correlation effects beyond the random phase approximation

2003 ◽  
Vol 67 (4) ◽  
Author(s):  
J. M. Pitarke ◽  
J. P. Perdew
Keyword(s):  
Surface Energy ◽  
Metal Surface ◽  
Random Phase Approximation ◽  
Short Range ◽  
Random Phase ◽  
Phase Approximation ◽  
Correlation Effects ◽  
Short Range Correlation ◽  
Range Correlation

SHORT-RANGE CORRELATION EFFECTS IN A POLARON GAS IN GaAs–AlGaAs QUANTUM WELL WIRES

1999 ◽  
Vol 13 (22n23) ◽  
pp. 819-827 ◽  
Author(s):  
ANTÔNIO NEWTON BORGES ◽  
FRANCISCO A. P. OSÓRIO ◽  
PAULO CÉSAR MIRANDA MACHADO ◽  
OSCAR HIPÓLITO
Keyword(s):  
Quantum Well ◽  
Short Range ◽  
Rectangular Cross Section ◽  
Random Phase ◽  
Field Approximation ◽  
Correlation Effects ◽  
Short Range Correlation ◽  
Electronic Density ◽  
Quantum Well Wire ◽  
Range Correlation

We investigate the short-range correlation effects of plasmon–phonon collective excitations in a quantum well wire by using the self-consistent field approximation theory proposed by Singwi, Tosi, Land and Sjolander [Phys. Rev.176, 589 (1968)]. In our calculation model, we consider a three-subband model with only one populated, for a rectangular cross-section quantum well wire with infinite height for the potential barrier. We have verified that by decreasing the wire width (and/or decreasing the electronic density), the local field correction effects are increased. We compare the present results with those obtained within the Random Phase Approximation throughout the paper and found that the differences between the two calculation methods are more significant for the intrasubband plasmon.

DIELECTRIC THEORY OF PLASMA OSCILLATIONS AND ITS EXTENSION TO THE EXCITON PROBLEM

1963 ◽  
Vol 41 (9) ◽  
pp. 1470-1481
Author(s):  
C. Horie
Keyword(s):  
Dispersion Relation ◽  
Charge Density ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Phase Approximation ◽  
Correlation Effects ◽  
Plasma Oscillations ◽  
Local Charge ◽  
New Form ◽  
Plasma Problem

A new form of the microscopic expression for the dielectric constant is derived and used to obtain the dispersion relation for plasma modes. It is found that the usual dispersion relation for plasma modes derived using the random phase approximation contains higher-order correlation effects than is usually believed. The dielectric approach to the plasma problem is extended to the exciton problem by introducing a nonlocal charge density instead of the local charge density appearing in the case of the plasma modes. The same equation determining the energy of the exciton states as derived in a previous paper is obtained.

scholarly journals Elastic scattering of low-energy positron by atom

2005 ◽  
Vol 3 (2) ◽  
pp. 141-149 ◽  
Author(s):  
M.R. Nikolic ◽  
Aleksandar Tancic
Keyword(s):  
Elastic Scattering ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Dyson Equation ◽  
Low Energy ◽  
Phase Approximation ◽  
Correlation Effects ◽  
Slow Positron ◽  
Theoretical Results

In this paper, we present our calculation for the elastic scattering of the slow positron from atoms. The calculation is performed for He, Ne, Xe and Kr. In the calculations we used Random phase approximation. By slowing Dyson equation we take into account the correlation effects. Our results are consistent with experimental and other theoretical results.

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