Analysis of low-dimensional semiconductor nanostructures with a self-consistent iterative scheme

2006 ◽  
Author(s):  
D. Roy Mahapatra ◽  
Roderick V. N. Melnik
Keyword(s):  
Iterative Scheme ◽  
Semiconductor Nanostructures ◽  
Self Consistent ◽  
Low Dimensional

scholarly journals Low-dimensional chaos in the single wave model for self-consistent wave–particle Hamiltonian

2021 ◽  
Vol 31 (8) ◽  
pp. 083104
Author(s):  
J. V. Gomes ◽  
M. C. de Sousa ◽  
R. L. Viana ◽  
I. L. Caldas ◽  
Y. Elskens
Keyword(s):  
Wave Model ◽  
Single Wave ◽  
Self Consistent ◽  
Low Dimensional

scholarly journals Entropic measure unveils country competitiveness and product specialization in the World trade web

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gianluca Teza ◽  
Michele Caraglio ◽  
Attilio L. Stella
Keyword(s):  
Iterative Scheme ◽  
Entropy Function ◽  
Bipartite Networks ◽  
Complexity Measures ◽  
Wide Range ◽  
Self Consistent ◽  
Set Up ◽  
Technical Features ◽  
Country Competitiveness ◽  
Entropic Measure

AbstractWe show how the Shannon entropy function can be used as a basis to set up complexity measures weighting the economic efficiency of countries and the specialization of products beyond bare diversification. This entropy function guarantees the existence of a fixed point which is rapidly reached by an iterative scheme converging to our self-consistent measures. Our approach naturally allows to decompose into inter-sectorial and intra-sectorial contributions the country competitivity measure if products are partitioned into larger categories. Besides outlining the technical features and advantages of the method, we describe a wide range of results arising from the analysis of the obtained rankings and we benchmark these observations against those established with other economical parameters. These comparisons allow to partition countries and products into various main typologies, with well-revealed characterizing features. Our methods have wide applicability to general problems of ranking in bipartite networks.

Fascinating World of Nanomaterials, Applications and Technology Hurdles in Commercial Production

2009 ◽  
Vol 1209 ◽  
Author(s):  
Shiva Hullavarad ◽  
Nilima Hullavarad
Keyword(s):  
Quantum Confinement ◽  
Building Blocks ◽  
Semiconductor Nanostructures ◽  
Commercial Production ◽  
Scientific Field ◽  
Bohr Radius ◽  
Semiconducting Nanowires ◽  
Size Dependent ◽  
Low Dimensional ◽  
De Broglie Wavelength

AbstractNanoparticles, nanowires, nanorods and other kinds of nanostructures have been of great interest to scientific field. Semiconducting nanowires have attracted much attention due to the fact that reduced dimensional confinement of electrons, holes and photons make them particularly attractive as potential building blocks for nanoscale optoelectronic devices, highly quantum efficient lasers and non-linear optical converters. It is generally accepted that the low dimensional structures (where the size in one direction is equivalent to or smaller than the de Broglie wavelength) are useful materials for investigating the dependence of electrical and thermal transport or mechanical properties on the dimensionality and quantum confinement. Nanomaterials also play an important role as functional units in fabricating the electromechanical devices. Semiconductor nanostructures of different materials and shapes are investigated due to their size dependent electronic properties observable at dimensions comparable to or less than Bohr radius of exciton in these materials. Especially various oxides and sulphides have generated interests in variety of applications. In this paper, the recent progress in various nanostructures, paradigms in implementation and technology hurdles in implementing nanostructures are discussed

scholarly journals Atmospheric models for LBV’s at minimum and maximum states

1989 ◽  
Vol 113 ◽  
pp. 285-286
Author(s):  
Claus Leitherer ◽  
Werner Schmutz ◽  
David C. Abbott ◽  
Ana V. Torres-Dodgen ◽  
Wolf-Rainer Hamann ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Radiative Transfer ◽  
Iterative Scheme ◽  
Atmospheric Models ◽  
Self Consistent ◽  
Self Consistency

We study the relation between photospheric and wind parameters of LBV’s on the basis of self-consistent atmospheric models. Our theoretical model consists of a spherically extended, dynamical NLTE atmosphere for the radiative transfer and a modified CAK code for the hydrodynamics. These codes are combined in an iterative scheme to achieve self-consistency.

scholarly journals Self-consistent Full-band Modeling of Quantum Semiconductor Nanostructures

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 91-95 ◽  
Author(s):  
Francesco Chirico ◽  
Aldo Di Carlo ◽  
Paolo Lugli
Keyword(s):  
Semiconductor Nanostructures ◽  
Bloch Functions ◽  
Mos Structure ◽  
Poisson Equations ◽  
Full Band ◽  
Self Consistent ◽  
Efficient Integration ◽  
Quantum Semiconductor

We have developed a full-band pseudopotential-based approach to describe semiconductor nanostructures. The method relies on the bulk Bloch functions expansion of the system wavefunction, which guarantee an efficient integration of the full-band approach in self-consistent schemes where Schroedinger and Poisson equations are solved iteratively. In order to gain efficiency of the method a suitable separation between structure dependent and material dependent contributions to the system hamiltonian is presented. Results are shown for a typical Si/SiO2 MOS structure.

Spin currents in semiconductor nanostructures: A non-equilibrium Green-function approach

2017 ◽  
Author(s):  
Branislav K. Nikolic ◽  
Liviu P. Zarbo ◽  
Satofumi Souma
Keyword(s):  
Green Function ◽  
Spin Current ◽  
Semiconductor Nanostructures ◽  
Pure Spin ◽  
Current Operator ◽  
Spin Orbit ◽  
Spin Currents ◽  
Low Dimensional ◽  
Green Function Approach ◽  
Non Equilibrium

This article examines spin currents and spin densities in realistic open semiconductor nanostructures using different tools of quantum-transport theory based on the non-equilibrium Green function (NEGF) approach. It begins with an introduction to the essential theoretical formalism and practical computational techniques before explaining what pure spin current is and how pure spin currents can be generated and detected. It then considers the spin-Hall effect (SHE), and especially the mesoscopic SHE, along with spin-orbit couplings in low-dimensional semiconductors. It also describes spin-current operator, spindensity, and spin accumulation in the presence of intrinsic spin-orbit couplings, as well as the NEGF approach to spin transport in multiterminal spin-orbit-coupled nanostructures. The article concludes by reviewing formal developments with examples drawn from the field of the mesoscopic SHE in low-dimensional spin-orbit-coupled semiconductor nanostructures.

MODELING HETEROSTRUCTURES WITH SCHRÖDINGER–POISSON–NAVIER ITERATIVE SCHEMES, EFFECT OF CARRIER CHARGE, AND INFLUENCE OF ELECTROMECHANICAL COUPLING

NANO ◽  
2012 ◽  
Vol 07 (04) ◽  
pp. 1250031 ◽  
Author(s):  
D. ROY MAHAPATRA ◽  
M. WILLATZEN ◽  
R. V. N. MELNIK ◽  
B. LASSEN
Keyword(s):  
Boundary Conditions ◽  
Electromechanical Coupling ◽  
Level Energy ◽  
Displacement Boundary ◽  
Coupling Case ◽  
Self Consistent ◽  
Type Semiconductor ◽  
Full Solution ◽  
Low Dimensional ◽  
Carrier Charge

This paper presents a detailed investigation of the effects of piezoelectricity, spontaneous polarization and charge density on the electronic states and the quasi-Fermi level energy in wurtzite-type semiconductor heterojunctions. This has required a full solution to the coupled Schrödinger–Poisson–Navier model, as a generalization of earlier work on the Schrödinger–Poisson problem. Finite-element-based simulations have been performed on a AlN/GaN quantum well by using both one-step calculation as well as the self-consistent iterative scheme. Results have been provided for field distributions corresponding to cases with zero-displacement boundary conditions and also stress-free boundary conditions. It has been further demonstrated by using four case study examples that a complete self-consistent coupling of electromechanical fields is essential to accurately capture the electromechanical fields and electronic wavefunctions. We have demonstrated that electronic energies can change up to approximately 0.5 eV when comparing partial and complete coupling of electromechanical fields. Similarly, wavefunctions are significantly altered when following a self-consistent procedure as opposed to the partial-coupling case usually considered in literature. Hence, a complete self-consistent procedure is necessary when addressing problems requiring more accurate results on optoelectronic properties of low-dimensional nanostructures compared to those obtainable with conventional methodologies.

Flexible low-dimensional semiconductor field emission cathodes: fabrication, properties and applications

2017 ◽  
Vol 5 (41) ◽  
pp. 10682-10700 ◽  
Author(s):  
Shanliang Chen ◽  
Weiyou Yang
Keyword(s):  
Field Emission ◽  
Semiconductor Nanostructures ◽  
Low Dimensional ◽  
Field Emission Cathodes

We present an overview on the fabrication, properties, and applications of flexible field emission cathodes based on low-dimensional semiconductor nanostructures.

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