scholarly journals Quantum Transport Simulation of the DOS function, Self-Consistent Fields and Mobility in MOS Inversion Layers

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 21-25 ◽  
Author(s):  
Dragica Vasileska ◽  
Terry Eldridge ◽  
Paolo Bordone ◽  
David K. Ferry
Keyword(s):  
Quantum Transport ◽  
Born Approximation ◽  
Inversion Layer ◽  
The Self ◽  
Charge Densities ◽  
Self Energy ◽  
Self Consistent ◽  
Inversion Charge ◽  
Simulation Results ◽  
Subband Structure

We describe a simulation of the self-consistent fields and mobility in (100) Si-inversion layers for arbitrary inversion charge densities and temperatures. A nonequilibrium Green's functions formalism is employed for the state broadening and conductivity. The subband structure of the inversion layer electrons is calculated self-consistently by simultaneously solving the Schrödinger, Poisson and Dyson equations. The self-energy contributions from the various scattering mechanisms are calculated within the self-consistent Born approximation. Screening is treated within RPA. Simulation results suggest that the proposed theoretical model gives mobilities which are in excellent agreement with the experimental data.

scholarly journals Inelastic quantum transport in nanostructures: The self-consistent Born approximation and correlated electron-ion dynamics

2008 ◽  
Vol 78 (3) ◽  
Author(s):  
Eunan J. McEniry ◽  
Thomas Frederiksen ◽  
Tchavdar N. Todorov ◽  
Daniel Dundas ◽  
Andrew P. Horsfield
Keyword(s):  
Quantum Transport ◽  
Born Approximation ◽  
The Self ◽  
Ion Dynamics ◽  
Correlated Electron ◽  
Self Consistent

scholarly journals Self-Consistent Calculation of Particle-Hole Diagrams on the Matsubara Frequency: Flex Approximation

1997 ◽  
Vol 08 (05) ◽  
pp. 1145-1158
Author(s):  
J. J. Rodríguez-Núñez ◽  
S. Schafroth
Keyword(s):  
Hubbard Model ◽  
Imaginary Part ◽  
Chemical Potential ◽  
Order Approximation ◽  
The Self ◽  
Green Functions ◽  
Matsubara Frequency ◽  
Self Energy ◽  
Peak Structure ◽  
Self Consistent

We implement the numerical method of summing Green function diagrams on the Matsubara frequency axis for the fluctuation exchange (FLEX) approximation. Our method has previously been applied to the attractive Hubbard model for low density. Here we apply our numerical algorithm to the Hubbard model close to half filling (ρ =0.40), and for T/t = 0.03, in order to study the dynamics of one- and two-particle Green functions. For the values of the chosen parameters we see the formation of three branches which we associate with the two-peak structure in the imaginary part of the self-energy. From the imaginary part of the self-energy we conclude that our system is a Fermi liquid (for the temperature investigated here), since Im Σ( k , ω) ≈ w2 around the chemical potential. We have compared our fully self-consistent FLEX solutions with a lower order approximation where the internal Green functions are approximated by free Green functions. These two approches, i.e., the fully self-consistent and the non-self-consistent ones give different results for the parameters considered here. However, they have similar global results for small densities.

Vacancies in close-packed polyvalent metals

1970 ◽  
Vol 316 (1525) ◽  
pp. 201-222 ◽  
Keyword(s):  
Bloch Wave ◽  
Wave Functions ◽  
The Self ◽  
Radial Wave ◽  
Conduction Electrons ◽  
Self Energy ◽  
Crystal Density ◽  
Self Consistent ◽  
The One ◽  
Formation Energies

The difference in total energy of a crystal with and without a vacancy involves essentially three terms: (i) The change in the one-electron eigenvalues due to scattering of conduction electrons off the vacant site. (ii) The self-energy of the displaced charge. (iii) The change in exchange and correlation energies of the electron gas. We have investigated the contributions (i) to (iii) for Cu, Mg, Al and Pb. The change in the one-electron eigenvalues is shown to be insensitive to the Bloch wave character of the wave functions and also to the choice of the repulsive potential V ( r ) representing the effect of the vacancy on the conduction electrons. There is thus no difficulty in evaluating contribution (i) for metals of different valencies. In contrast, the self-energy of the displaced charge is shown to depend very sensitively on the choice of V ( r ), and it is, therefore, essential to make the calculation self-consistent. This we have done by properly screening the negative of the point ion fields for Cu + to Pb 4+ . The radial wave functions and phase shifts for the low order partial waves have been evaluated, and self-consistent displaced charges obtained. The exchange energy has been estimated from a Dirac–Slater type of approximation and is again not sensitive to the detailed form of the displaced charge, while the change in correlation energy is found to be unimportant in determining the vacancy formation energy. The formation energies for the polyvalent metals are in satisfactory agreement with experiment. Some results for excess resistivities due to vacancies in metals are also presented. Here, in contrast to the calculation of the formation energies, it is essential to account for the Bloch wave character of the electron waves scattered by the vacancy. It is also proposed that the displaced charge round a vacancy may be a useful building block (or pseudoatom) for forming the crystal density.

Investigation of Dielectric Decrement and Correlation Effects on Electric Double-Layer Capacitance by Self-Consistent Field Model

2016 ◽  
Vol 20 (2) ◽  
pp. 441-458 ◽  
Author(s):  
Manman Ma ◽  
Shuangliang Zhao ◽  
Zhenli Xu
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Electrode Materials ◽  
Layer Structure ◽  
Differential Capacitance ◽  
The Self ◽  
Gaussian Field ◽  
Image Charge ◽  
Self Energy ◽  
Self Consistent

AbstractThe differential capacitance of electric double-layer capacitors is studied by developing a generalized model of the self-consistent Gaussian field theory. This model includes many-body effects of particles near the interface such as ionic sizes, the order of water alignment and electrostatic correlations, and thus can present more accurate predictions of the electric double-layer structure and hence the capacitance than traditional continuum theories. Analytical simplification of the model and efficient numerical method are introduced, in particular, the approximation of the self-Green's function which describes the self energy of a mobile ion. We show that, when the applied voltage on interfaces is small the dielectric effect of the electrode materials plays an important role. For large voltage, this effect is screened, but the dielectric saturation due to the alignment of the nearby water is shown to be essential. For 2:1 electrolytes, abnormal enhancement on the capacitance due to the dielectric electrode is observed, which is due to the interplay of the image charge effect and Born solvation energy in the self energy of ions.

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