Analytical calculation of scattering from spin impurity and entanglement generation for edge states of Kane–Mele model

2022 ◽  
pp. 115127
Author(s):  
J. Ahmadi ◽  
M. Soltani ◽  
G. Rashedi
Keyword(s):  
Analytical Calculation ◽  
Edge States ◽  
Entanglement Generation

Monte Carlo Modelling of Secondary Electron Yield from Rough Surfaces

1990 ◽  
Vol 48 (1) ◽  
pp. 422-423
Author(s):  
John C. Russ
Keyword(s):  
Monte Carlo ◽  
Energy Loss ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Analytical Calculation ◽  
Mean Free Path ◽  
Single Scattering ◽  
High Energy ◽  
Secondary Electron Yield ◽  
Electron Yield

Monte-Carlo programs are well recognized for their ability to model electron beam interactions with samples, and to incorporate boundary conditions such as compositional or surface variations which are difficult to handle analytically. This success has been especially powerful for modelling X-ray emission and the backscattering of high energy electrons. Secondary electron emission has proven to be somewhat more difficult, since the diffusion of the generated secondaries to the surface is strongly geometry dependent, and requires analytical calculations as well as material parameters. Modelling of secondary electron yield within a Monte-Carlo framework has been done using multiple scattering programs, but is not readily adapted to the moderately complex geometries associated with samples such as microelectronic devices, etc.This paper reports results using a different approach in which simplifying assumptions are made to permit direct and easy estimation of the secondary electron signal from samples of arbitrary complexity. The single-scattering program which performs the basic Monte-Carlo simulation (and is also used for backscattered electron and EBIC simulation) allows multiple regions to be defined within the sample, each with boundaries formed by a polygon of any number of sides. Each region may be given any elemental composition in atomic percent. In addition to the regions comprising the primary structure of the sample, a series of thin regions are defined along the surface(s) in which the total energy loss of the primary electrons is summed. This energy loss is assumed to be proportional to the generated secondary electron signal which would be emitted from the sample. The only adjustable variable is the thickness of the region, which plays the same role as the mean free path of the secondary electrons in an analytical calculation. This is treated as an empirical factor, similar in many respects to the λ and ε parameters in the Joy model.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Lifetime Regime in the Electrically-Detected Transient Grating Method Applied to Amorphous and Microcrystalline Silicon Films

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Sanguino ◽  
M. Niehus ◽  
S. Koynov ◽  
P. Brogueira ◽  
R. Schwarz ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Analytical Calculation ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Dielectric Relaxation Time ◽  
Transient Grating ◽  
Minority Carrier Diffusion Length ◽  
Carrier Recombination ◽  
Thin Silicon ◽  
Good Agreement

AbstractThe minority-carrier diffusion length in thin silicon films can be extracted from the electrically-detected transient grating method, EDTG, by a simple ambipolar analysis only in the case of lifetime dominated carrier transport. If the dielectric relaxation time, τdiel, is larger than the photocarrier response time, τR, then unexpected negative transient signals can appear in the EDTG result. Thin silicon films deposited by hot-wire chemical vapor deposition (HWCVD) near the amorphous-to-microcrystalline transition, where τR varies over a large range, appeared to be ideal candidates to study the interplay between carrier recombination and dielectric response. By modifying the ambipolar description to allow for a time-dependent carrier grating build-up and decay we can obtain a good agreement between analytical calculation and experimental results.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

scholarly journals Epitaxial Growth of Quasi-One-Dimensional Bismuth-Halide Chains with Atomically Sharp Topological Non-Trivial Edge States

ACS Nano ◽  
2021 ◽  
Author(s):  
Jincheng Zhuang ◽  
Jin Li ◽  
Yundan Liu ◽  
Dan Mu ◽  
Ming Yang ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Edge States ◽  
One Dimensional

scholarly journals Group Velocity Modulation and Light Field Focusing of the Edge States in Chirped Valley Graphene Plasmonic Metamaterials

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1808
Author(s):  
Liqiang Zhuo ◽  
Huiru He ◽  
Ruimin Huang ◽  
Shaojian Su ◽  
Zhili Lin ◽  
...  
Keyword(s):  
Group Velocity ◽  
Light Field ◽  
Slow Light ◽  
Dielectric Materials ◽  
Degree Of Freedom ◽  
Geometrical Parameters ◽  
Edge States ◽  
Velocity Modulation ◽  
Plasmonic Metamaterials ◽  
On Chip

The valley degree of freedom, like the spin degree of freedom in spintronics, is regarded as a new information carrier, promoting the emerging valley photonics. Although there exist topologically protected valley edge states which are immune to optical backscattering caused by defects and sharp edges at the inverse valley Hall phase interfaces composed of ordinary optical dielectric materials, the dispersion and the frequency range of the edge states cannot be tuned once the geometrical parameters of the materials are determined. In this paper, we propose a chirped valley graphene plasmonic metamaterial waveguide composed of the valley graphene plasmonic metamaterials (VGPMs) with regularly varying chemical potentials while keeping the geometrical parameters constant. Due to the excellent tunability of graphene, the proposed waveguide supports group velocity modulation and zero group velocity of the edge states, where the light field of different frequencies focuses at different specific locations. The proposed structures may find significant applications in the fields of slow light, micro–nano-optics, topological plasmonics, and on-chip light manipulation.

Theoretical realization of two-dimensional Dirac/Weyl line-node and traversing edge states in penta-X2Y monolayers

2021 ◽  
Vol 23 ◽  
pp. 101057
Author(s):  
Lirong Wang ◽  
Lei Jin ◽  
Guodong Liu ◽  
Ying Liu ◽  
Xuefang Dai ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Edge States ◽  
Line Node

scholarly journals Stability of topological edge states under strong nonlinear effects

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
Rajesh Chaunsali ◽  
Haitao Xu ◽  
Jinkyu Yang ◽  
Panayotis G. Kevrekidis ◽  
Georgios Theocharis
Keyword(s):  
Nonlinear Effects ◽  
Edge States
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