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6 results on '"Hueckel method"'

1. Quantum computation with photochromic films in a Mach–Zehnder interferometer.

Author

Scotognella, Francesco

Subjects
PHOTON detectors, QUANTUM communication, QUANTUM computing, REFRACTIVE index, LIGHT absorption, PHOTOCHROMIC materials
Abstract

Photochromic materials are of great interest because they enable the fabrication of photo-activated switches. In this study, an experiment is proposed in which two chromene-based photochromic layers were inserted into the arms of a Mach–Zehnder interferometer. The chromene was studied from the perspective of optical absorption to determine the wavelength-dependent complex refractive index. Impinging ultraviolet light on one of the chromene layers induces a transition from the closed to the open form of the chromene, resulting in different phase shifts in the two arms of the interferometer. This results in a change in the probability of detecting a photon by the two detectors after the second mirror of the Mach–Zehnder interferometer. The experiment may be of interest to researchers working in the fields of quantum information and quantum communications. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Quantum computation with photochromic films in a Mach–Zehnder interferometer

Author

Francesco Scotognella

Subjects
photochromic materials, Mach–Zehnder interferometer, complex refractive index, Hueckel method, quantum communication, Chemical technology, TP1-1185
Abstract

Photochromic materials are of great interest because they enable the fabrication of photo-activated switches. In this study, an experiment is proposed in which two chromene-based photochromic layers were inserted into the arms of a Mach–Zehnder interferometer. The chromene was studied from the perspective of optical absorption to determine the wavelength-dependent complex refractive index. Impinging ultraviolet light on one of the chromene layers induces a transition from the closed to the open form of the chromene, resulting in different phase shifts in the two arms of the interferometer. This results in a change in the probability of detecting a photon by the two detectors after the second mirror of the Mach–Zehnder interferometer. The experiment may be of interest to researchers working in the fields of quantum information and quantum communications.

Published
2024
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3. Theoretical study of the effects of the number and location of N and O atoms on the relative thermodynamic stability of polyheterocyclic compounds.

Author

Yangfu, Li, Heming, Shchao, Pivina, T., Batog, L., Lebedev, O., and Khmel'nitskii, L.

Abstract

The thermodynamic stability of a number of tricyclic conjugated compounds has been evaluated on the basis of the composition of the occupied molecular orbitals and Hueckel molecular orbital calculations. The relative stability of the compounds under study depends on the number and location of the nitrogen and oxygen atoms in their structures. [ABSTRACT FROM AUTHOR]

Published
1993
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4. Kinetic Studies on the Photochemically Activated Solvation of[(.eta.6-arene1)Ru(.eta.6-arene2)]2+ Sandwich Compounds

Author

Andreas Ludi, Thomas Karlen, and Andreas Hauser

Subjects
Solvation, Photochemistry, Medicinal chemistry, Inorganic Chemistry, chemistry.chemical_compound, Cationic complex, Transition metal Complexes, Hexamethylbenzene, Hueckel method, Physical and Theoretical Chemistry, Acetonitrile, Mesitylene, Photolysis, Platinoid Complexes, Anisole, Toluene, Hapto complex, Solvent, Ruthenium Complexes, chemistry, Sandwich compound, Organic ligand, Quantum yield
Abstract

Irradiation of the inert complexes ((η6-arene1)Ru(η6-arene2)]2+ (arene=benzene, toluene, mesitylene, hexamethylbenzene, anisole, biphenyl, naphthalene, chrysene) in various solvents (H2O/H+, H2O/H+/EtOH, acetonitrile, DMSO) leads to the fully solvated complexes (Ru(solvent)6]2+. The reaction occurs in two consecutive steps. The first step is the formation of the intermediate ((η6-arene)Ru(solvent)3]2+ with either arene1 or arene2 being replaced by solvent.

Published
1994
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5. Nouveaux matériaux photoluminescents activés au cuivre monovalent

Author

Jacob, Alain, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Université Sciences et Technologies - Bordeaux I, and Claude Parent

Subjects
Absorption X, Delafossite, HÜCKEL Etendues, Glasses, Oxides, Band calculation, Phosphate, Band structure, [CHIM.MATE]Chemical Sciences/Material chemistry, Cuivre monovalent, X-ray absorption, CuTh2(PO4)3, Verres d'oxydes, ASW, Monovalent copper, Hueckel method, Photoluminescence, ASW (Augmented Spherical Waves), Borate, Calculs de structures de bandes
Abstract

Les propriétés spectroscopiques du cuivre monovalent ont été étudiées dans deux familles de matériaux oxygénés.Deux types de verres borate et phosphate, de composition nominales LaMgB5O10:Cu+ et LiLaP4O12:Cu+ ont été caractérisés, essentiellement par spectroscopie UV-visible et par EXAFS. Des tests d'émission laser ont été effectués sur un échantillon de verre borate.Trois matériaux-modèle fortement concentrés en cuivre, dans lesquels cet élément adopte une coordinence linéaire par rapport à l'oxygène, ont fait l'objet de tentatives de modélisation visant à corréler structure et propriétés de spectroscopie optique. Il s'agit des delafossites CuLaO2 et CuYO2 ainsi que du phosphate CuTh2(PO4)3. Des calculs de structures de bandes ont été effectués pour les composés CuLaO2 et CuYO2 par les méthodes ASW et HÜCKEL ETENDUE. L'étude spectroscopique de CuTh2(PO4)3 a été étendue à la solution solide Na1-xCuxTh2(PO4)3 (0 < x < 0,25).; non disponible

Published
1997

6. The Hueckel Model for Small Metal Clusters. 4. Orbital Properties and Cohesive Energies for Model Clusters of Up to Several Hundred Atoms

Author

STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY, Lindsay, D. M., Wang, Youqi, George, Thomas F., STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY, Lindsay, D. M., Wang, Youqi, and George, Thomas F.

Abstract

We examine model cluster structures by applying the simple Hueckel method to spherically symmetric clusters whose atoms are constrained to occupy cubic (simply, body-centered or face-centered) and hcp lattice positions. The Hueckel orbitals are organized into energy shells, many of which remain well separated even at 500-600 atom cluster sizes. The classical droplet model provides a good fit to cluster atomization energies, which then correctly extrapolate to the bulk cohesive energy predicted by tight binding calculations. Energy level distributions for cubic lattice show that features characteristic of a tight binding solid become fully evident in clusters containing as few as 100 atoms. A particular example is the high density of states found for the Fermi level of bcc clusters, vestiges of which might suffice to confer on suitable materials an enhance electrical conductivity. (AW), Prepared in cooperation with California Institute of Technology, Pasadena, CA. and City University of New York, NY.

Published
1989

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