Electronic and vibrational modes on a Penrose lattice: Localized states and band structure

Mahito Kohmoto; Bill Sutherland

doi:10.1103/physrevb.34.3849

LOCALIZED STATES AND BAND STRUCTURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1972304 ◽

1972 ◽

Vol 33 (C3) ◽

pp. C3-21-C3-25 ◽

Cited By ~ 3

Author(s):

F. BASSANI

Keyword(s):

Band Structure ◽

Localized States

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Calculation of the band structure and density of localized states of materials of the quasi-binary system Zn3As2–Mn3As2

Solid State Communications ◽

10.1016/j.ssc.2021.114237 ◽

2021 ◽

Vol 328 ◽

pp. 114237

Author(s):

V.S. Zakhvalinskii ◽

T.B. Nikulicheva ◽

E.A. Pilyuk ◽

A.S. Kubankin ◽

O.N. Ivanov ◽

...

Keyword(s):

Binary System ◽

Band Structure ◽

Localized States ◽

Density Of Localized States ◽

Quasi Binary System

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Complex band structure and localized states on solid surfaces

International Journal of Quantum Chemistry ◽

10.1002/qua.560040747 ◽

2009 ◽

Vol 4 (S3B) ◽

pp. 847-848

Author(s):

Mojmír Tomášek

Keyword(s):

Band Structure ◽

Solid Surfaces ◽

Localized States

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Empirical Tight-Binding Applied to Silicon Nanoclusters

MRS Proceedings ◽

10.1557/proc-491-299 ◽

1997 ◽

Vol 491 ◽

Cited By ~ 2

Author(s):

G. Allan ◽

C. Delerue ◽

M. Lannoo

Keyword(s):

Band Structure ◽

Nearest Neighbor ◽

Good Description ◽

Tight Binding ◽

Localized States ◽

Basis Set ◽

Band Structure Calculation ◽

Minimal Basis ◽

Tight Binding Approximation ◽

Bulk Band

ABSTRACTThe calculation of the electronic structure of silicon nanostructures is used to discuss the accuracy of results obtained by the tight-binding method. We first show that the level of refinement of the tight-binding approximation must be adapted to the calculated property. For example, an accurate description of both the valence and conduction bands which can be achieved with a 3rd-nearest neighbor approximation is necessary to calculate the variation of the gap energy with the silicon crystallite size. The sp3s* model which gives a bad description of the conduction band underestimates the confinement energy but can give good results when it is used to determine the variation of the crystallite band gap with pressure. To study Si-III (BC-8) nanocrystallites, we show that a good description of the bulk band structure can be obtained with non-orthogonal tight-binding but due to the large number of nearest neighbors one must take analytical variations of the parameter with interatomic distances. The parameters involved in these expressions can be easily fitted to the bulk band structures using the k-point symmetry without requiring the use of group theory. Finally we discuss the effect of increasing the size of the minimal-basis set and we show that it would be possible to get the values of the tight-binding parameters from a first-principles localized states band structure calculation avoiding the fit to the energy dispersion curves.

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Band Structure and Electronic Excitations in Cdl-xMnxTe

MRS Proceedings ◽

10.1557/proc-89-197 ◽

1986 ◽

Vol 89 ◽

Author(s):

Su-Huai Wei ◽

Alex Zunger

Keyword(s):

Band Structure ◽

Localized States ◽

Electronic Excitations ◽

Many Body ◽

Band Structure Calculations ◽

Spin Polarized ◽

Semiconductor Alloy ◽

Schematic Energy Level Diagram ◽

The Many ◽

Structure Calculations

AbstractWe have performed spin-polarized, self-consistent local spin density total energy and band structure calculations for the prototype semimagnetic semiconductor alloy Cd1-xMnxTe. Based on the calculated band structures and taking into account the many body effects of localized states, we propose a schematic energy level diagram to interpret the d→d*, p→d, and photoemission transitions in Cd1-xMnxTe.

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Electronic structure near the band gap of heavily nitrogen doped GaAs and GaP

MRS Proceedings ◽

10.1557/proc-692-h2.1.1 ◽

2001 ◽

Vol 692 ◽

Cited By ~ 2

Author(s):

Yong Zhang ◽

B. Fluegel ◽

M. Hanna ◽

A. Duda ◽

A. Mascarenhas

Keyword(s):

Band Structure ◽

Band Gap ◽

Doping Level ◽

Bound States ◽

Nitrogen Doping ◽

Localized States ◽

Nitrogen Doped ◽

Band Structure Calculations ◽

Level 3 ◽

Structure Calculations

AbstractIsoelectronic impurity nitrogen atoms have been found to generate a series of localized states in GaP and GaAs. These states can be either bound (within the band gap) or resonant (above the band gap) when in the dilute doping limit (roughly < 1019 cm−3 for GaP and < 1018 cm−3 for GaAs). With increasing nitrogen doping level, a shift of the absorption edge from the binary band gap has been observed for the so-called GaPN or GaAsN alloy. We discuss the similarity and dissimilarity between the two systems in the following aspects: (1) How does the nitrogen doping perturb the host band structure? (2) How do the nitrogen bound states evolve with increasing nitrogen doping level? (3) What are the dominant contributors to the band edge absorption? And (4) does a universal model exist for GaPN and GaAsN? Other issues that will be discussed are: how does one define the band gap for these materials, and what is the relevance of various theoretical band structure calculations to the experimentally measured parameters.

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STRUCTURE AND STABILITY OF THE DX CENTERS IN GaAs AND InP

Modern Physics Letters B ◽

10.1142/s0217984995000462 ◽

1995 ◽

Vol 09 (09) ◽

pp. 511-530 ◽

Cited By ~ 1

Author(s):

K. J. CHANG ◽

BYOUNG-HO CHEONG

Keyword(s):

Hydrostatic Pressure ◽

Band Structure ◽

Atomic Structure ◽

Chemical Bonding ◽

Theoretical Studies ◽

Vibrational Modes ◽

Level Transition ◽

Dx Center ◽

The Stability ◽

Microscopic Origin

We review some of the recent theoretical studies on the atomic structure, the stability, and the vibrational modes of donor-induced defect levels in GaAs and InP. For Si and S donors, the microscopic origin of the DX center is investigated and a review is given of the shallow-to-deep DX level transition under hydrostatic pressure. We also discuss the band structure and the chemical bonding effects on the stability of donor impurities, which are associated with broken-bond and breathing-mode lattice relaxations.

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Exploring the FTIR, Optical and Nuclear Radiation Shielding Properties of Samarium-Borate Glass: A Characterization through Experimental and Simulation Methods

Nanomaterials ◽

10.3390/nano11071713 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1713

Author(s):

Shams A. M. Issa ◽

Hesham M. H. Zakaly ◽

Huseyin O. Tekin ◽

Heba A. Saudi ◽

Ali Badawi ◽

...

Keyword(s):

Radiation Shielding ◽

Localized States ◽

Nuclear Radiation ◽

Oxide Content ◽

Content Increase ◽

Simulation Methods ◽

Vibrational Modes ◽

Gamma Photon ◽

Spectral Peaks ◽

Shielding Properties

(Tl2O3)30-(Li2O)10-(B2O3)(60−y)-(Sm2O3)y glass system with various Sm2O3 additives (y = 0, 0.2, 0.4, 0.6) was studied in detail. The vibrational modes of the (Tl2O3)30-(Li2O)10-(B2O3)(60−y) network were active at three composition-related IR spectral peaks that differed from those mixed with Samarium (III) oxide at high wavenumber ranges. These glass samples show that their permeability increased with the Samarium (III) oxide content increase. Additionally, the electronic transition between localized states was observed in the samples. The MAC, HVL, and Zeff values for radiation shielding parameters were calculated in the energy range of 0.015–15 MeV using the FLUKA algorithm. In addition, EBF, EABF, and ΣR values were also determined for the prepared glasses. These values indicated that the parameters for shielding (MAC, HVL, Zeff, EBF, EABF, and ΣR) are dependent upon the Samarium (III) oxide content. Furthermore, the addition of Samarium (III) oxide to the examined glass samples greatly reinforced their shielding capacity against gamma photon. The findings of the current study were compared to analyses of the XCOM software, some concretes, and lead. In the experiment, it was found that the SMG0.6 glass sample was the strongest shield.

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