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Surface Effects on Wannier Excitons in Superlattices:Monte Carlo Simulation

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Chinese Physics Letters 2002年第8期19卷 1164-1167页

作者： K. Afif A. Benyoussef J. Diouri Laboratoire de Magnétisme Faculté des Sciences BP 1014 Rabat Morocco groupe d'Electronique et de physique du Solide Faculté des Sciences BP 2121 Tetouan Morocco

Using a Monte Carlo quadrature, we calculate by a variational method the binding energy Eb of Wannier excitons in N-period m-CdMnTe/n-CdTe superlattices, including or not including the step discontinuity in the potential barrier at the interface, and with varying N as well as well width. The calculation is performed in the framework of the effective mass approximation for both heavy-hole and light-hole excitons. The degree of exciton localization dependence on these parameters is accurately illustrated.

关键词： Monte Carlo methods

Exact Solution of D-Dimensional Klein-Gordon Oscillator with Minimal Length

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Communications in Theoretical Physics 2010年第2期53卷 231-236页

作者： Y.Chargui L.Chetouani A.Trabelsi Unit de Recherche de physique Nuclaire et des Hautes Energies Facult des Sciences de Tunis Dpartement de physique Thorique Institut de Physique Universit de Constantine Route Ain El Bey Unite de Recherche de physique Nucleaire et des Hautes Energies Faculte des Sciences de Tunis Centre National des Sciences et Technologies Nuclaires

Specific modifications of the usual canonical commutation relations between position and momentumoperators have been proposed in the literature in order to implement the idea of the existence of a minimal observablelength. Here, we study a consequence of this proposal in relativistic quantum mechanics by solving in the momentumspace representation the Klein-Gordon oscillator in arbitrary dimensions. The exact bound states spectrum and thecorresponding momentum space wave function are obtained. Following Chang et al. (Phys. Rev. D 65 (2002) 125027),we discuss constraint that can be placed on the minimal length by measuring the energy levels of an electron in a penningtrap.

关键词： Klein-Gordon oscillator minimal length energy spectrum

Auto-correlation Effects on the sp^3-d Exchange Interaction in Cd1-x MnxTe/CdTe Multilayers

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Chinese Physics Letters 2002年第11期19卷 1679-1682页

作者： K. Afif A. Benyoussef J. Diouri Laboratoire de Magnétisme Faculté des Sciences B.P. 1014 Rabat Morocco groupe d'Electronique et de physique du Solide Faculté des Sciences B.P. 2121 Tetouan Morocco

Band offsets and total energy of Wannier excitons in multilayers are affected by dimensional and auto-correlation effects, and sp3-d coupling is consequently modified. Thus, the calculation of the Zeeman splitting in the quantum wells has to take into account these effects, especially when the mismatch cannot be disregarded. In this work, the theoretical study of these combined effects has been performed for Cd1-xMnxTe/CdTe multilayers embedded by Cd1-yZnyTe as the substrate (or the buffer) on one side and as a cladding layer on the other side. This sample allows us to highlight the role played by the substrate (buffer) and the growth direction on the Zeeman splitting in such multilayers.

关键词： Multilayers

Comparative Study of Entanglement and Wigner Function for Multi-Qubit GHZ-Squeezed State

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Communications in Theoretical Physics 2017年第12期67卷 729-734页

作者： Fatima-Zahra Siyouri Laboratoire de physique Thèorique Département de Physique Faculté des Sciences Université Mohammed Ⅴ-Agdal

In this paper we address the possibility of using the Wigner function to capture the quantum entanglement present in a multi-qubit system. For that purpose, we calculate both the degree of entanglement and the Wigner function for mixed tripartite squeezed states of Greenberger–Horne–Zeilinger(GHZ) type then we compare their behaviors. We show that the role of Wigner function in detecting and quantifying bipartite quantum correlation [Int. J. Mod. Phys. B30(2016) 1650187] may be generalized to the multipartite case.

关键词： negativity of Wigner function entanglement squeezed states tripartite GHZ non-classicality

Surface morphology and electrochemical characterization of electrodeposited Ni-Mo nanocomposites as cathodes for hydrogen evolution

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Chinese Physics B 2015年第10期24卷 559-563页

作者： Elhachmi Guettaf Temam Hachemi Ben Temam Said Benramache Laboratoire de physique des Couches Minces et Applications Université de Biskra

In this work, we study the influences of current density on surface morphology and electrochemical characterization of electrodeposited Ni-Mo. The Ni-Mo composite coatings are deposited on pretreated copper substrates by electrolytic deposition. The Ni-Mo solution is taken from nickel sulfate fluid and ammonium heptamolybdate with 10 g/l. The Ni-Mo composite coatings are deposited at a temperature of 303 K with an applied current density of j dep= 10 A/dm2-30 A/*** find that the corrosion resistance is improved by incorporating Mo particles into Ni matrix in 0.6-M Na Cl solution. From the potentiodynamic polarization curve of electrodeposited Ni-Mo it is confirmed that the corrosion resistance decreases with increasing applied current density. The x-ray diffraction（XRD） analyses of Ni-Mo coatings indicate three phases of Mo Ni4, Mo1.24Ni0.76, and Ni3 Mo phases crystallites of nickel and molybdenum. The scanning electronic microscopy（SEM） tests indicate that Ni-Mo coatings present cracks and pores.

关键词： Ni-Mo electrolytic deposition corrosion resistance potentiodynamic polarization plating current density

Geodesic equation in non-commutative gauge theory of gravity

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Chinese Physics C 2022年第10期46卷 193-206页

作者： Abdellah Touati Slimane Zaim Laboratoire de physique des Rayonnements et de leurs Interactions avec la Matiere departement de physique Faculte des Sciences de la Matiere Universite de Batna-1Batna 05000Algeria departement de physique Faculte des Sciences de la Matière Universitéde Batna-1Batna 05000Algeria

In this study,we construct a non-commtative gauge theory of the modified structure of the gravitational field using the Seiberg-Witten map and the general tetrad fields of Schwarzschild space-time to show that the noncommutative geometry removes the singularity at the origin of the black hole,thus obtaining a non-singular Schwarzschild black *** geodetic structure of this black hole presents new types of motion next to the event horizon within stable orbits that are not allowed by the ordinary Schwarzschild *** noncommutative periastron advance of the Mercury orbit is obtained,and with the available experimental data,we find a parameter of non-commutativity on the order of 10^(-25)s·kg^(-1).This result shows that the new fundamental length,√h■,is on the order of 10^(-31)m.

关键词： non-commutative geometry gauge gravity Schwarzschild space-time geodesic equation

Tensile-WAXD Apparatus:An Improved and Accurate System for the In situ Study of Extension-induced Segmental Orientation in Highly Stretched Elastomer

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Chinese Journal of Polymer Science 2024年第12期42卷 2002-2010,I0011页

作者： Xiang Shi Center for Advanced Material Diagnostic Technology Shenzhen Technology UniversityShenzhen518118China Laboratoire de physique des solides CNRSUniversitéParis-SudUniversitéParis-SaclayOrsay91400France

An improved X-ray apparatus that combines tensile testing and X-ray diffraction has been designed and constructed to conduct timeresolved experiments during uniaxial *** utilizing mortise-like clamping jaws and dogbone-shaped specimens,this setup allows for the simultaneous recording of high-quality mechanical responses and 2D diffraction patterns due to the minimization of experimental errors from sample slippage or premature ***,the local extension ratio can be accurately determined based on thickness variation,and the Hermans'orientation function was demonstrated to be a reliable method with high accuracy to calculate the segmental orientation parameter〈P_(2)〉in elastomeric samples under high degree of *** summary,this innovative tensile-WAXD instrument has proven to be a promising and powerful technique for investigating the“stress-deformation-segmental orientation”relationship in elastomers with high extensibilities.

关键词： X-ray apparatus Elongation calculation Segmental orientation In situ measurement

Enhanced dielectric performance of Dy-substituted YMn2O5 for high-frequency applications

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Progress in Natural Science:Materials International 2021年第5期31卷 762-771页

作者： H.Chouaibi K.Khirouni E.Dhahri Laboratoire de physique Appliquée Faculté des Sciences Université de Sfax Laboratoire de physique des Matériaux et des Nanomatériaux Appliquée à l'Environnement Faculté des Sciences de Gabès Cité Erriadh Université de Gabès

The dielectric performances as well as the effects of Dy3+ions content at A sites of YMn2O5(YMO) [x=0(YDM0)and x=0.4(YDM0.4)] polycrystalline samples were *** compounds were synthesized via sol-gel method.X-Ray diffraction and Raman measurements proved the high quality of the compounds that crystallized in an orthorhombic structure with the Pbam space ***,impedance spectroscopy and electrical modulus studies revealed that both samples exhibited a non-debye’s type of *** decrease of impedance for YDM0.4compared to the pure YDM0,may be attributed to the decrease in charge transfer *** the fit of impedance spectra,they confirmed that both compounds were simultaneously capacitive and ***,the activation energies obtained from Modulus and complex impedance were proven to be neighboring,suggesting that the relaxation process refers to electron *** each compound,the evolution of ε’and tan & with temperature indicated a clearer relaxor behavior,namely the existence of two *** first one detected at low temperature is related to the charge carriers hopping between Mn3+and Mn4+and the second at high temperature is associated with oxygen *** reduced hopping rate with Dy3+substitution for Y3+ions at A sites is responsible for the decrease in dielectric constant and dielectric *** significant findings demonstrate that these materials can be invested in a fruitful use in UV photo-detector and power applications in high frequency as microwave,millimeter wave signal processing,for civilian,military and space applications.

关键词： Multiferroic Relaxation phenomenon High dielectric constant Relaxor behavior

Exact solution of the one-dimensional Klein-Gordon equation with scalar and vector linear potentials in the presence of a minimal length

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Chinese Physics B 2010年第2期19卷 43-47页

作者： Y Chargui L Chetouani A Trabelsi Unit de Recherche de physique Nuclaire et des Hautes Energies Facult des Sciences de Tunis Dpartement de physique Thorique Institut de PhysiqueUniversit de ConstantineRoute Ain El BeyConstantineAlgeria Centre National des Sciences et Technologies Nuclaires Technopole de Sidi-Thabet 2020Tunisia

Using the momentum space representation, we solve the Klein--Gordon equation in one spatial dimension for the case of mixed scalar and vector linear potentials in the context of deformed quantum mechanics characterized by a finite minimal uncertainty in position. The expressions of bound state energies and the associated wave functions are exactly obtained.

关键词： Klein--Gordon equation linear potential minimal length exact solution