scholarly journals Resonant Raman scattering by charge-density and single-particle excitations in semiconductor nanostructures: A generalized interband-resonant random-phase-approximation theory

2002 ◽  
Vol 65 (12) ◽  
Author(s):  
Daw-Wei Wang ◽  
S. Das Sarma
Keyword(s):  
Raman Scattering ◽  
Charge Density ◽  
Approximation Theory ◽  
Single Particle ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Semiconductor Nanostructures ◽  
Phase Approximation ◽  
Resonant Raman ◽  
Resonant Raman Scattering

Interpretation of Preferential Adsorption Using Random Phase Approximation Theory

1995 ◽  
Vol 60 (10) ◽  
pp. 1641-1652 ◽  
Author(s):  
Henri C. Benoît ◽  
Claude Strazielle
Keyword(s):  
Approximation Theory ◽  
Random Phase Approximation ◽  
Virial Coefficient ◽  
Random Phase ◽  
Second Virial Coefficient ◽  
Solvent Mixture ◽  
Gyration Radius ◽  
Thermodynamic Quantities ◽  
Phase Approximation ◽  
Preferential Adsorption

It has been shown that in light scattering experiments with polymers replacement of a solvent by a solvent mixture causes problems due to preferential adsorption of one of the solvents. The present paper extends this theory to be applicable to any angle of observation and any concentration by using the random phase approximation theory proposed by de Gennes. The corresponding formulas provide expressions for molecular weight, gyration radius, and the second virial coefficient, which enables measurements of these quantities provided enough information on molecular and thermodynamic quantities is available.

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 Estimation of nuclear matrix elements of double-$$\varvec{\beta }$$ decay from shell model and quasiparticle random-phase approximation

2021 ◽  
Vol 136 (9) ◽  
Author(s):  
J. Terasaki ◽  
Y. Iwata
Keyword(s):  
Shell Model ◽  
Nuclear Matrix ◽  
Single Particle ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Nuclear Matrix Element ◽  
Phase Approximation ◽  
Quasiparticle Random Phase Approximation ◽  
Calculation Results ◽  
The Many

AbstractThe nuclear matrix element (NME) of neutrinoless double-$$\beta $$ β ($$0\nu \beta \beta $$ 0 ν β β ) decay is an essential input for determining the neutrino effective mass, if the half-life of this decay is measured. Reliable calculation of this NME has been a long-standing problem because of the diversity of the predicted values of the NME, which depends on the calculation method. In this study, we focus on the shell model and the QRPA. The shell model has a rich amount of the many-particle many-hole correlations, and the quasiparticle random-phase approximation (QRPA) can obtain the convergence of the calculation results with respect to the extension of the single-particle space. It is difficult for the shell model to obtain the convergence of the $$0\nu \beta \beta $$ 0 ν β β NME with respect to the valence single-particle space. The many-body correlations of the QRPA may be insufficient, depending on the nuclei. We propose a new method to phenomenologically modify the results of the shell model and the QRPA compensating for the insufficiencies of each method using the information of other methods in a complementary manner. Extrapolations of the components of the $$0\nu \beta \beta $$ 0 ν β β NME of the shell model are made toward a very large valence single-particle space. We introduce a modification factor to the components of the $$0\nu \beta \beta $$ 0 ν β β NME of the QRPA. Our modification method yields similar values of the $$0\nu \beta \beta $$ 0 ν β β NME for the two methods with respect to $$^{48}$$ 48 Ca. The NME of the two-neutrino double-$$\beta $$ β decay is also modified in a similar but simpler manner, and the consistency of the two methods is improved.

A random phase approximation theory of nuclear relaxation in CuO2planes

1990 ◽  
Vol 67 (9) ◽  
pp. 5079-5081 ◽  
Author(s):  
N. Bulut ◽  
D. W. Hone ◽  
D. J. Scalapino ◽  
N. E. Bickers
Keyword(s):  
Approximation Theory ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Nuclear Relaxation ◽  
Phase Approximation

Resonant Raman scattering from a charge-density-wave system (TTF-TCNQ)

1998 ◽  
Vol 105 (7) ◽  
pp. 427-431 ◽  
Author(s):  
J.E. Eldridge ◽  
Y. Lin ◽  
T.C. Mayadunne ◽  
L.K. Montgomery ◽  
S. Kaganov ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Wave System ◽  
Resonant Raman ◽  
Resonant Raman Scattering ◽  
A Charge
Sign in / Sign up

Export Citation Format

Share Document