scholarly journals Plasmon modes in Dirac–Schrödinger hybrid electron systems including layer-thickness and exchange-correlation effects

2018 ◽  
Vol 96 (6) ◽  
pp. 615-621 ◽  
Author(s):  
Nguyen Van Men ◽  
Nguyen Quoc Khanh
Keyword(s):  
Layer Thickness ◽  
Random Phase ◽  
Dielectric Constants ◽  
Monolayer Graphene ◽  
Correlation Effects ◽  
Layer System ◽  
Optical Branch ◽  
Exchange Correlation ◽  
Damping Rate ◽  
Double Layer System

We calculate the plasmon dispersion relation and damping rate of collective excitations in a double-layer system consisting of monolayer graphene and GaAs quantum well at zero temperature including layer-thickness and exchange-correlation effects. We use the generalized random-phase-approximation dielectric function and take into account the nonhomogeneity of the dielectric background of the system. We show that the effects of layer thickness, electron densities, and exchange-correlations are more pronounced for acoustic modes, while the optical branch depends remarkably on dielectric constants of the contacting media.

Plasmon modes in bilayer-graphene–GaAs heterostructures including layer-thickness and exchange-correlation effects

2018 ◽  
Vol 32 (23) ◽  
pp. 1850256 ◽  
Author(s):  
Nguyen Van Men ◽  
Dong Thi Kim Phuong
Keyword(s):  
Quantum Well ◽  
Layer Thickness ◽  
Random Phase ◽  
Bilayer Graphene ◽  
Monolayer Graphene ◽  
Layer System ◽  
Exchange Correlation ◽  
Quantum Well Width ◽  
Double Layer System ◽  
Plasmon Modes

We investigate the dispersion relation and decay rate of plasmon modes in a double-layer system made of bilayer graphene (BLG) and infinite GaAs quantum well at zero-temperature within the generalized random-phase-approximation and taking into account the 2DEG layer-thickness and inhomogeneity of the background dielectric. We illustrate that the acoustic plasmon dispersion curve of the considered system differs significantly from that of monolayer graphene (MLG)–GaAs heterostructure and BLG–GaAs without layer-thickness. Calculations also demonstrate that meanwhile the optical plasmon curve is affected slightly by spacer width and exchange-correlation, the acoustic one depends remarkably on the interlayer distance, inhomogeneity of the background dielectric, carrier densities, spacer dielectric constant, quantum well width and exchange-correlations.

Plasmon modes in graphene — GaAs heterostructures at finite temperature

2019 ◽  
Vol 33 (16) ◽  
pp. 1950174 ◽  
Author(s):  
Nguyen Van Men ◽  
Dong Thi Kim Phuong
Keyword(s):  
Quantum Well ◽  
Finite Temperature ◽  
Random Phase ◽  
Monolayer Graphene ◽  
Layer System ◽  
Exchange Correlation ◽  
Plasmon Frequency ◽  
Quantum Well Width ◽  
Double Layer System ◽  
Plasmon Modes

This paper is to investigate the dispersion relation and decay rate of plasmon modes in a double layer system made of monolayer graphene (MLG) and infinite GaAs quantum well at finite temperature within the generalized random-phase-approximation and taking into account the 2DEG layer-thickness and the inhomogeneity of the background dielectric. Calculations demonstrate that when the quantum well width increases, the acoustic (AC) plasmon frequency decreases dramatically, but the optical (OP) one seems unchanged. In addition, the results also illustrate that the temperature and separated distance affect significantly both AC and OP plasmon modes of the system. Finally, the dielectric of the background acts strongly on the OP plasmon curve while carrier density in two layers and exchange-correlation effects only lead to remarkable changes for the acoustic one.

scholarly journals Application of time-dependent current-density-functional theory to nonlocal exchange-correlation effects in polymers

2003 ◽  
Vol 118 (3) ◽  
pp. 1044-1053 ◽  
Author(s):  
M. van Faassen ◽  
P. L. de Boeij ◽  
R. van Leeuwen ◽  
J. A. Berger ◽  
J. G. Snijders
Keyword(s):  
Density Functional Theory ◽  
Current Density ◽  
Density Functional ◽  
Time Dependent ◽  
Correlation Effects ◽  
Functional Theory ◽  
Exchange Correlation

On the role of steric and exchange–correlation effects in halogenated complexes

2021 ◽  
Author(s):  
Mojtaba Alipour ◽  
Parisa Fallahzadeh
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Partitioning ◽  
Correlation Effects ◽  
Functional Theory ◽  
Exchange Correlation

Density functional theory formalisms of energy partitioning schemes are utilized to find out what energetic components govern interactions in halogenated complexes.

scholarly journals Characteristics of Oceanic Warm Cloud Layers within Multilevel Cloud Systems Derived by Satellite Measurements

Atmosphere ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 465 ◽  
Author(s):  
Yuhao Ding ◽  
Qi Liu ◽  
Ping Lao
Keyword(s):  
Double Layer ◽  
Lower Layer ◽  
Single Layer ◽  
Distribution Patterns ◽  
Radar Data ◽  
Multilayered Structures ◽  
Layer System ◽  
Cloud Systems ◽  
Warm Cloud ◽  
Double Layer System

Low-level warm clouds are a major component in multilayered cloud systems and they are generally hidden from the top-down view of satellites with passive measurements. This study conducts an investigation on oceanic warm clouds embedded in multilayered structures by using spaceborne radar data with fine vertical resolution. The occurrences of warm cloud overlapping and the geometric features of several kinds of warm cloud layers are examined. It is found that there are three main types of cloud systems that involve warm cloud layers, including warm single layer clouds, cold-warm double layer clouds, and warm-warm double layer clouds. The two types of double layer clouds account for 23% and in the double layer occurrences warm-warm double layer subsets contribute about 13%. The global distribution patterns of these three types differ from each other. Single-layer warm clouds and the lower warm clouds in the cold-warm double layer system they have nearly identical geometric parameters, while the upper and lower layer warm clouds in the warm-warm double layer system are distinct from the previous two forms of warm cloud layers. In contrast to the independence of the two cloud layers in cold-warm double layer system, the two kinds of warm cloud layers in the warm-warm double layer system may be coupled. The distance between the two layers in the warm-warm double layer system is weakly dependent on cloud thickness. Given the upper and lower cloud layer with moderate thickness of around 1 km, the cloudless gap reaches its maximum when exceeding 600 m. The cloudless gap decreases in thickness as the two cloud layers become even thinner or thicker.

Revisiting Local Electric Fields on Close-Packed Metal Surfaces: Theory Versus Experiments

2007 ◽  
Vol 128 ◽  
pp. 219-224 ◽  
Author(s):  
P.P. Kostrobiy ◽  
Bogdan M. Markovych ◽  
Yuri Suchorski
Keyword(s):  
Electron Density ◽  
Electric Fields ◽  
Metal Surfaces ◽  
Integration Method ◽  
Functional Integration ◽  
Correlation Effects ◽  
Flat Surfaces ◽  
Exchange Correlation ◽  
Density Distributions ◽  
Theory Versus

An external electrostatic field of the order of a few tens of a volt per nanometer causes significant changes in the electron density distribution near a metal surface. Because of differing electronic distributions and varying responses of electrons to the applied field for various metals, the resulting local field distribution in the close vicinity of the surface should depend on the electronic properties of the particular metal, even for flat surfaces. Field-free and field-modified electron density distributions for different metal surfaces were calculated using the functional integration method. This approach enables the exchange-correlation effects to be correctly considered and makes it possible to account for the proper field-effect for broad field ranges without using the perturbation theory. The results of calculations are compared with the field-ion microscopic observations.

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