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1 1 of :27 ISI Web of Knowledge Page 1 (Articles ) [ 1 ] Record 1 of 31 (Popov, D.); Pop, N (Pop, N.); Luminosu, I (Luminosu, I.); Chiritoiu, V (Chiritoiu, V.) Title: Density matrix approach of the excitation on coherent states of the pseudoharmonic oscillator Source: EPL, 87 (4): Art. No AUG 2009 KeyWords Plus: QUANTUM OPTICS Abstract: We have examined the excitation on coherent states of the pseudoharmonic oscillator which are obtained by repeated action of the raising operator on the usual coherent states. By using the density matrix approach, we have examined some interesting properties (including the nonclassicality) of these states, both in pure and also in mixed (thermal) cases. Copyright (C) EPLA, 2009 Addresses: [Popov, D.; Pop, N.; Luminosu, I.; Chiritoiu, V.] Politehn Univ Timisoara, Dept Phys Fdn Engn, Timisoara , Romania Reprint Address: Popov, D, Politehn Univ Timisoara, Dept Phys Fdn Engn, B Dul V Parvan,2, Timisoara , Romania. Address: nicolina.pop@et.upt.ro ISSN: Article Number: DOI: / /87/44003 Record 2 of 31 (Popov, Dusan); Pop, N (Pop, Nicolina); Sajfert, V (Sajfert, Vjekoslav) Editor(s): Bunoiu, M; Malaescu, I Title: Excitation on the Coherent States of Pseudoharmonic Oscillator Source: PROCEEDINGS OF THE PHYSICS CONFERENCE TIM-08, 1131: Book series title: AIP Conference Proceedings Conference Title: Physics Conference 2008 (TIM-08) Conference Date: NOV 28-29, 2008 Conference Location: Timisoara, ROMANIA Author Keywords: coherent states; pseudoharmonic oscillator; density matrix Abstract: In the last decades, much attention has been paid to the excitation on coherent states, especially for coherent states of the harmonic oscillator ([1] and references therein). But an interesting anharmonic oscillator with many potential applications is also the pseudoharmonic oscillator (PHO). So, in the present paper we have defined the excitation on the Klauder-Perelomov coherent states (E-KP-CSs) for the PHO. These states are obtained by repeatedly operating the raising operator K+ on a usual Klauder-Perelomov coherent state (KP-CS) of the PHO [2]. We have verified that really, the E-KP-CSs fulfill all the properties of the coherent states, as stated by Klauder [3]. We have examined the nonclassical properties of the E-KP-CSs, by using the density matrix formalism and examining the dependence of the Mandel parameter Q(z,k;m)(vertical bar z vertical bar(2)) on the vertical bar z vertical bar(2) and on the m. It seems that these states can be used in optical communication field and in the physics of quantum information, as signal beams, due to the fact that in these fields the nonclassicality plays an important role. Addresses: [Popov, Dusan; Pop, Nicolina] Univ Politehn, Dept Phys, Fdn Eng, Timisoara , Romania Reprint Address: Popov, D, Univ Politehn, Dept Phys, Fdn Eng, Bd Vasile Parvan 2, Timisoara , Romania. ISSN: X ISBN: Record 3 of 31 (Popov, D.); Sajfert, V (Sajfert, V.) Title: Pair-coherent states of the pseudoharmonic oscillator Source: PHYSICA SCRIPTA, T135: Art. No JUL 2009 Conference Title: 15th Central European Workshop on Quantum Optics

2 2 of :27 Conference Date: MAY 29-JUN 03, 2008 Conference Location: Belgrade, SERBIA KeyWords Plus: QUANTUM INFORMATION Abstract: In the paper, we have constructed and examined some properties of pair-coherent states of Barut-Girardello kind for two noninteracting subsystems of pseudoharmonic oscillators. The pseudoharmonic oscillator obeys SU(1,1) group symmetry, which was extensively used to study many problems in quantum optics and quantum information theory. Addresses: [Popov, D.] Univ Politehn Timisoara, Timisoara , Romania; [Sajfert, V.] Univ Novi Sad, Tech Fac M Pupin Zrenjanin, Zrenjanin 23000, Serbia Reprint Address: Popov, D, Univ Politehn Timisoara, B Dul 5 Parvan 2, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk; sajfertv@vektor.net ISSN: Article Number: DOI: / /2009/T135/ Record 4 of 31 Author(s): Sajfert, V (Sajfert, Vjekoslav); Popov, D (Popov, Dusan); Maskovic, L (Maskovic, Ljiljana); Tosic, B (Tosic, Bratislav) Title: Behaviour of Thin Magnetic Films at Low Temperatures Source: JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE, 6 (5): MAY 2009 Author Keywords: Ultrathin Magnetic Films; Low Temperature Magnetization; Exact Bose Representation; Two Small Parameters Autoreduction; Qualitative Difference Nano- and Macrostructures KeyWords Plus: CYLINDRICAL QUANTUM DOTS; GREEN FUNCTIONS; MOLECULAR FILMS; FERROMAGNETISM; PHYSICS; MODEL Abstract: The problem of the analysis of low temperature magnetization is exposed in detail. The application of exact Bose representation of spin operators to the bulk ferromagnets is justified. By means of this representation the magnetization of ultrathin films was analysed. It turned out that thin films magnetization contains exponentially small terms characterized by Dyson's functions even in harmonical approximation. The main conclusions of this work are that magnetic lattice of thin film is more rigid than the macroscopic lattice and that the autoreduction process (the three layer film divides onto three two layer subfilms) takes place in the film. Addresses: [Sajfert, Vjekoslav] Tech Fac Mihajlo Pupin, Zrenjanin 23000, Serbia; [Popov, Dusan] Univ Politech, Timisoara , Romania; [Maskovic, Ljiljana] Acad Criminalist & Police Studies, Belgrade 11000, Serbia; [Tosic, Bratislav] Vojvodina Acad Sci & Arts, Novi Sad 21000, Serbia Reprint Address: Sajfert, V, Tech Fac Mihajlo Pupin, Zrenjanin 23000, Serbia. ISSN: DOI: /jctn Record 5 of 31 Author(s): Luminosu, I (Luminosu, I.); Popov, D (Popov, D.); Zaharie, I (Zaharie, I.) Title: Spectral Absorption of Unpolarized Light Through Nano-Materials in the Absence of a Magnetic Field Source: SCIENCE OF SINTERING, 40 (3): SEP-DEC 2008 Author Keywords: Aggregates; Absorption; Biphasic; Colloidal; Extinction KeyWords Plus: FLUIDS Abstract: A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid - liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid). The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles). The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized nm are formed in the system. The average number of nanoparticles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications. Addresses: [Luminosu, I.; Popov, D.; Zaharie, I.] Univ Politehn Timisoara, Dept Tech Phys, Timisoara , Romania

3 3 of :27 Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Tech Phys, B Dul Vasile Parvan 2, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk ISSN: X DOI: /SOS L Record 6 of 31 Author(s): Sajfert, V (Sajfert, Vjekoslav); Popov, D (Popov, Dusan); Tosic, B (Tosic, Bratislav) Title: Low-temperature magnetization in nanofilms Source: PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, 388 (4): FEB Author Keywords: Ultrathin magnetic films; Low-temperature magnetization; Exact Bose representation; Two small parameters autoreduction; Qualitative difference nano and macrostructures KeyWords Plus: CYLINDRICAL QUANTUM DOTS; THIN MOLECULAR FILMS; PHYSICS Abstract: The low-temperature magnetization of a film was analyzed by the use of exact Bose representation of spin operators that does not suffer from the presence of unphysical states. The magnetization of thin films has exponentially small temperature correctness, so that Dyson's proof about exponentially small correction coming from two bosons at ideal lattice point cannot be used in film analyses. The main conclusions of this work are that magnetic lattice of a thin film is more rigid than the macroscopic lattice and that the autoreduction process (the three layer film divides into two layer subfilms) takes place in the film. (C) 2008 Elsevier B.V. All rights reserved. Addresses: [Popov, Dusan] Polytech Univ, Timisoara, Romania; [Tosic, Bratislav] Vojvodina Acad Sci & Arts, Novi Sad, Serbia Address: sajfertv@ptt.rs; dusan_popov@yahoo.co.uk; btosic@yahoo.com ISSN: DOI: /j.physa Record 7 of 31 Author(s): Sajfert, V (Sajfert, Viekoslav); Maskovic, L (Maskovic, Ljiljana); Jacimovski, S (Jacimovski, Stevo); Popov, D (Popov, Dusan); Tosic, B (Tosic, Bratislav) Title: Electron-Phonon Interaction in Cylindrical Nanostructures Source: JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE, 5 (7): JUL 2008 Author Keywords: Nano Cross-Section; BCS Approach; Critical Superconductive Temperature; Magnetic Field Produced by Disc Currents KeyWords Plus: SUPERCONDUCTIVITY; MODEL Abstract: The superconductivity properties of cylinder with nano cross-section are investigated. In the nearest neighbours approximation, electron Hamiltonian of cylinder decays onto two independent Hamiltonians. One corresponds to electrons which propagate along chains parallel to the axis of cylinder. Second correspond to electrons moving in discs. The electron-phonon interaction Hamiltonians are found and superconductive properties were examined in the frames of BCS approach. It was shown that superconductive temperature in chains is several Kelvins, while in discs it can be higher for two orders of magnitude. It is also shown that magnetic field produced by electron currents in discs is of the order of thousand Tesla, i.e., extremely high. Addresses: [Sajfert, Viekoslav] Univ Novi Sad, Tech Fac M Pupin, Zrenjanin 23000, Serbia; [Maskovic, Ljiljana] Acad Criminalist & Police Studies, Belgrade 11000, Serbia; [Jacimovski, Stevo] Univ Belgrade, Fac Elect Engn, Belgrade 11000, Serbia; [Popov, Dusan] Univ Politehn, Timisoara , Romania; [Tosic, Bratislav] Vojvodina Acad Sci & Arts, Novi Sad 21000, Serbia Reprint Address: Sajfert, V, Univ Novi Sad, Tech Fac M Pupin, Zrenjanin 23000, Serbia. ISSN: Record 8 of 31 Author(s): Gruescu, C (Gruescu, C.); Nicoara, I (Nicoara, I.); Popov, D (Popov, D.); Bodea, R (Bodea, R.); Hora, H (Hora, H.) Title: Optical glass compatibility for the design of apochromatic systems Source: SCIENCE OF SINTERING, 40 (2): MAY-AUG 2008 Author Keywords: optical glass compatibility; triplet design; image quality; large aperture; aspherical surface

4 4 of :27 Abstract: The design of apochromatic systems is difficult because of two problems: the glass sorts compatibility and the c(1)/c(a) arbitrary input ratio. The optical glass manufacturers offer a wide range of sorts, so that the choice of triplet compatible glasses becomes itself an important separate problem. The paper provides a solution of mathematical modeling for the glass compatibility and, practically, analyses the sorts presented by Schott GmbH. The original software provided 22 compatible glass triplets. The authors explored the possibilities of enlarging the c(1)/c(a) ratio from the value 0.6 indicated in the literature to a range of [ ]. Therefore, they designed and analyzed a set of 88 triplets. A correct glass choice can insure twice-larger apertures than the traditional ones for best quality apochromats (diffraction-limited). Addresses: [Popov, D.] Univ Politehn Timisoara, Dept Tech Phys, RO Timisoara, Romania; [Gruescu, C.; Nicoara, I.] Univ Politehn Timisoara, Mechatron Dept, RO Timisoara, Romania; [Bodea, R.; Hora, H.] Univ Oradea, Precis Mech Dept, RO Oradea, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Tech Phys, B Dul Vasile Parvan 2, RO Timisoara, Romania. Address: dusan_popov@yahoo.co.uk ISSN: X DOI: /SOS G Record 9 of 31 (Popov, Dusan); Sajfert, V (Sajfert, Vjekoslav); Zaharie, I (Zaharie, Ioan) Title: Pseudoharmonic oscillator and their associated Gazeau-Klauder coherent states Source: PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, 387 (16-17): JUL Author Keywords: coherent state; density operator; quantum information; qubit KeyWords Plus: SU(1,1); VIBRATIONS; SYSTEMS Abstract: In the paper we have constructed and examined the properties of the Gazeau-Klauder coherent states (GK-CSs) for the pseudoharmonic oscillator (PHO), one of three possible kinds in order to define the coherent states for this oscillator potential. In the second part, we have examined some nonclassical properties of these states. Our attention has been concentrated on the mixed states (thermal states). The diagonal P-representation of the corresponding density operator and some thermal expectations for the quantum canonical ideal gas of pseudoharmonic oscillators have also been examined. Like the CSs for the harmonic oscillator (HO), the GK-CSs for the PHO can be useful in the quantum information theory (QIT). (C) 2008 Elsevier B.V. All rights reserved. Addresses: [Popov, Dusan; Zaharie, Ioan] Univ Politech Timisoara, Dept Tech Phys, Timisoara , Romania; [Sajfert, Vjekoslav] Univ Novi Sad, Tech Fac M Pupin, Zrenjanin 23000, Serbia Reprint Address: Popov, D, Univ Politech Timisoara, Dept Tech Phys, B Dul Vasile Parvan 2, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk; sajfertv@ptt.yu; ioan.zaharie@fz.upt.ro Times Cited: 2 ISSN: DOI: /j.physa Record 10 of 31 (Popov, Dusan); Zaharie, I (Zaharie, Ioan); Sajfert, V (Sajfert, Vjekoslav); Luminosu, I (Luminosu, Ioan); Popov, D (Popov, Deian) Title: Quantum information in the frame of coherent states representation Source: INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS, 47 (5): MAY 2008 Author Keywords: quantum information; qubit; coherent state; density operator KeyWords Plus: PSEUDOHARMONIC OSCILLATOR; MORSE OSCILLATOR; ENTANGLEMENT Abstract: In this paper we have showed that the qubit can be expressed through the coherent states. Consequently, a message, i.e. a sequence of qubits, is expressed as a tensor product of coherent states. In the quantum information theory and practice, only the code and key message are expressed as a sequence of qubits, i.e. through a quantum channel, the properly information will be transmitted by using a classical channel. Even if the most used coherent states in the quantum information theory are the coherent states of the harmonic oscillator (particularly, expressing by them the Schrodinger "cat states" and the Bell states), several authors have been demonstrated that other kind of coherent states may be used in quantum information theory. For the ensembles of qubits, we must use the density operator, in order to describe the informational content of the ensemble. The diagonal representation of the density operator, in the coherent state representation, is also useful to examine the entanglement of the states.

5 5 of :27 Addresses: [Popov, Dusan; Zaharie, Ioan; Luminosu, Ioan] Univ Politehn Din Timisoara, Dept Fiz Techn, Timisoara , Romania; [Sajfert, Vjekoslav] Univ Novi Sad, Tech Fac Mihajlo Pupin, Zrenjanin, Serbia; [Popov, Deian] Alcatel Lucent Univ, Timisoara , Romania Reprint Address: Popov, D, Univ Politehn Din Timisoara, Dept Fiz Techn, B Dul V Parvan 2, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk Times Cited: 1 ISSN: DOI: /s Record 11 of 31 (Popov, D.); Zaharie, I (Zaharie, I.); Sajfert, V (Sajfert, V.); Popov, DD (Popov, D. D.) Editor(s): Cetin, SA; Hikmet, I Title: Coherent states and their role in quantum information theory Source: Six International Conference of the Balkan Physical Union, 899: Book series title: AIP CONFERENCE PROCEEDINGS Conference Title: 6th International Conference of the Balkan-Physical-Union Conference Date: AUG 22-26, 2006 Conference Location: Istanbul, TURKEY Author Keywords: quantum information; qubit; coherent state; density operator Abstract: The qubit, i.e. the fundamental unit of information in the quantum theory of information (QIT), can be expressed through the coherent states (CSs). Consequently, a message, i.e. a sequence of qubits, is a tensor product of CSs. For ensembles of qubits, it must use the density operator (DO), which can be written also in the CSs representation. Addresses: Univ Politehn, Timisoara, Romania Reprint Address: Zaharie, I, Univ Politehn, Timisoara, Romania. ISSN: X ISBN: Record 12 of 31 Author(s): Sajfert, V (Sajfert, Vjekoslav); Jacimovski, S (Jacimovski, Stevo); Popov, D (Popov, Dusan); Tosic, B (Tosic, Bratislav) Title: Statistical and dynamical equivalence of different elementary cells Source: JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE, 4 (3): MAY 2007 Author Keywords: statistical equivalence; dynamical equivalence; nanostructures; macroscopic structurest KeyWords Plus: CYLINDRICAL QUANTUM DOTS; THIN MOLECULAR FILMS Abstract: The method of achievement statistical and dynamical equivalence between rectangular and lower symmetry structures is proposed. The importance of this method is essential for analysis of broken symmetry structures (especially nanostructures). The method was applied to Heisenberg ferromagnet in Bloch's approximation. Although the method is not universal for triclinic structures, the practical field of its application is relative widely. If we deal with monoclinic structures method of equivalence is applicable always. Addresses: Univ Novi Sad, Tech Fac M Pupin, Novi Sad, Serbia; Univ Belgrade, Fac Elect Engn, Belgrade, Serbia; Univ Politech, Timisoara, Romania; Vojvodina Acad Sci & Arts, Novi Sad, Serbia Reprint Address: Sajfert, V, Univ Novi Sad, Tech Fac M Pupin, Novi Sad, Serbia. ISSN: Record 13 of 31 (Popov, Dusan); Sajfert, V (Sajfert, Vjekoslav); Tosic, B (Tosic, Bratislav) Title: Thermodynamic and kinetic properties of mechanical oscillations in thin films Source: INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 20 (24): SEP

6 6 of :27 Author Keywords: spatial indices; the new Green's function methodology; chemical potential; specific skin effect; electron concentrations KeyWords Plus: MGB2; SUPERCONDUCTIVITY; ELECTRON Abstract: The advanced methodology of Green's function method and application of this new methodology have resulted in a set of interesting conclusions concerning thin film properties. It has been concluded that thin films possess high superconductive, thermoisolation and acoustical isolation properties. It is also concluded that physical characteristics of thin films axe spatially dependent and that this spatial dependence can be the basis for widening of the nanostructures application field. Addresses: Univ Politehn, Timisoara, Romania; Univ Novi Sad, Tech Fac M Pupin, Dure Dakovica BB Zrenjan 23000, Serbia; Vojvodina Acad Sci & Arts, Novi Sad 21000, Serbia Reprint Address: Popov, D, Univ Politehn, Timisoara, Romania. Address: dusan_popov@yahoo.co.uk; sajfertv@ptt.yu ISSN: Record 14 of 31 (Popov, D.); Davidovic, DM (Davidovic, D. M.); Arsenovic, D (Arsenovic, D.); Sajfert, V (Sajfert, V.) Title: P-function of the pseudoharmonic oscillator in terms of Klauder-Perelomov coherent states Source: ACTA PHYSICA SLOVACA, 56 (4): AUG 2006 KeyWords Plus: VIBRATIONS Abstract: Using the Klauder-Perelomov coherent states of the pseudoharmonic oscillator Hamiltonian, corresponding diagonal P-representation for the density matrix of the gas of pseudoharmonic oscillators in thermal equilibrium is constructed. With a help of this new result, some corresponding characteristic thermal expectation values are obtained. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara , Romania; Vinca Inst Nucl Sci, Belgrade, Serbia; Inst Phys, Belgrade, Serbia; Univ Novi Sad, Tech Fac M Pupin, Novi Sad, Serbia Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Regina Maria 1, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk Times Cited: 5 ISSN: Record 15 of 31 ; Zaharie, I; Dong, SH Title: Photon-added coherent states for the Morse oscillator Source: CZECHOSLOVAK JOURNAL OF PHYSICS, 56 (2): FEB 2006 Author Keywords: coherent states; Morse oscillator; density matrix; thermal expectations KeyWords Plus: FRANCK-CONDON FACTORS; VIBRATIONAL EXCITATIONS; VIBRON MODEL; MOLECULES; OPERATORS; POTENTIALS; COULOMB; LADDER Abstract: In the paper we have constructed and investigated some properties of the Perelomov's "generalized coherent states" and photon-added coherent states for the Morse one-dimensional Hamiltonian (MO-PACSs), using the SU(2) group generators. We have found the integration measure in the resolution of unity and we have calculated some expectation values in the MO-PACSs representation. Using these states, the diagonal P-representation of the density operator is constructed as a new result for Morse potential. In addition, we have calculated some thermal expectation values for the quantum canonical diatomic gas of the Morse oscillators. Addresses: Univ Politecn Timisoara, Dept Phys, Timisoara , Romania; Inst Mexicano Petr, Programa Ingn Mol, Mexico City 07730, DF, Mexico Reprint Address: Popov, D, Univ Politecn Timisoara, Dept Phys, Piata Regina Maria 1,Of Postal 5, Timisoara , Romania. Address: dusan_popov@yahoo.co.uk Times Cited: 1 ISSN: Record 16 of 31 Author(s): Sajfert, V; Setrajcic, J; Popov, D; Tosic, B

7 7 of :27 Title: Difference equations in condensed matter physics and their application to exciton systems in thin molecular films Source: PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, 353: AUG Author Keywords: difference equations; variable coefficients; operator solving; excitons; boundary conditions Abstract: The main goal of this work is the development of the correct methodology of calculation of the Green's function of broken symmetry structures. The two methods were analysed and it was concluded that the direct method with the use of the translational operators is not convenient for the analyses of the exciton properties in thin molecular films. The second proposed method, consisting in translation of the difference equation with spatially variable parameter into the system of difference equations with constant parameters, was applied to thin molecular film and the solution of this system, being Green's function depending on two spatial indices, separately, was found exactly. With help of this Green's function the spatial dependence of exciton concentration was found. The significance of the obtained spatial dependence of exciton concentration is discussed and it was concluded that on the basis of the found spatial dependence of exciton concentration can be determined such boundary conditions of thin molecular film which lead to high exciton concentrations and consequently to the possibility of construction of high power lasers. (c) 2005 Elsevier B.V. All rights reserved. Addresses: Univ Novi Sad, Tech Fac Mihajlo Pupin, Zrenjanin 23000, Serbia Monteneg; Univ Novi Sad, Fac Sci, Inst Phys, Novi Sad, Serbia Monteneg; Univ Politechn, Timisoara, Romania; Univ Novi Sad, Vojvodina Acad Sci & Arts, Novi Sad 21000, Serbia Monteneg Reprint Address: Sajfert, V, Univ Novi Sad, Tech Fac Mihajlo Pupin, Djure Djakovica St Bb, Zrenjanin 23000, Serbia Monteneg. Address: sajfertv@ptt.yu Times Cited: 6 ISSN: DOI: /j.physa Record 17 of 31 Author(s): Daoud, M; Popov, D Title: Statistical properties of Klauder-Perelomov coherent states for the morse potential Source: INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 18 (3): JAN Author Keywords: coherent states; density matrix; Morse potential; statistical properties; diagonal representation KeyWords Plus: GENERALIZED INTELLIGENT STATES; POSCHL-TELLER POTENTIALS; PSEUDOHARMONIC OSCILLATOR Abstract: We present in this letter a realistic construction of the coherent states for the Morse potential using the Klauder-Perelomov approach. We discuss the statistical properties of these states, by deducing the Q- and P-distribution functions. The thermal expectations for the quantum canonical ideal gas of the Morse oscillators are also calculated. Addresses: Univ Ibn Zohr, Fac Sci, LPMC, Agadir, Morocco; Max Planck Inst Phys Complex Syst Dresden, Dresden, Germany; Univ Politehn Timisoara, Dept Phys, Timisoara, Romania Reprint Address: Popov, D, Str Aries 20,Sc D,Et 5,Ap 18, Timisoara 1900, Romania. Address: dpopov@etv.utt.ro Times Cited: 2 ISSN: Record 18 of 31 Title: Gazeau-Klauder quasi-coherent states for the Morse oscillator Source: PHYSICS LETTERS A, 316 (6): OCT Author Keywords: coherent states; Morse oscillator; density matrix; thermal expectations KeyWords Plus: DISCRETE Abstract: In the Letter, we have constructed and investigated some properties of the Gazeau-Klauder quasi-coherent states for the Morse potential, previously deduced by Roy and Roy. We have focused our attention on the thermal states and we have found the analytical form for the diagonal P-representation of the density operator. (C) 2003 Elsevier B.V. All rights reserved. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Regina Marina 1,Of Postal 5, Timisoara 1900, Romania. Times Cited: 11

8 8 of :27 ISSN: DOI: /j.physleta Record 19 of 31 Author(s): Dong, SH; Sun, GH; Popov, D Title: Group theory approach to the Dirac equation with a Coulomb plus scalar potential in D+1 dimensions Source: JOURNAL OF MATHEMATICAL PHYSICS, 44 (10): OCT 2003 Abstract: We generalize the Dirac equation to D+1 space-time. The conserved angular momentum operators and their quantum numbers are discussed. The eigenfunctions of the total angular momentums are calculated for both odd D and even D cases. The exact solutions of the D+1-dimensional radial equations of the Dirac equation with a Coulomb plus scalar potential are analytically presented by studying the Tricomi equations obtained from a pair of coupled first-order ones. The eigenvalues are also discussed in some detail. (C) 2003 American Institute of Physics. Addresses: Inst Mexicano Petr, Programa Ingn Mol, Mexico City 07730, DF, Mexico; Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Syst, Mexico City 01000, DF, Mexico; Univ Politehn timisoara, Dept Phys, Timisoara 1900, Romania; Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City, DF, Mexico Reprint Address: Dong, SH, Inst Mexicano Petr, Programa Ingn Mol, Lazaro Cardenas 152, Mexico City 07730, DF, Mexico. Address: dongsh2@yahoo.com Times Cited: 13 ISSN: DOI: / Record 20 of 31 Author(s): Setrajcic, JP; Stojkovic, SM; Mirjanic, DL; Vucenovic, SM; Popov, D Editor(s): Uskokovic, DP; Battiston, GA; Milonjic, SK; Rakovic, DI Title: Influence of the boundary conditions on the electron properties of thin films with two sublattices Source: CONTEMPORARY STUDIES IN ADVANCED MATERIALS AND PROCESSES - YUCOMAT IV, 413: Book series title: MATERIALS SCIENCE FORUM Conference Title: 4th Yugoslav-Materials-Research-Society Conference Conference Date: SEP 10-14, 2001 Conference Location: HERCEG NOVI, YUGOSLAVIA Author Keywords: electrons; sublattice; thin films Abstract: The dispersion law and spectral weights of electrons in perturbed thin film structures with two sublattices were derived by the method of two-time, single-electron Green's functions. At variance with simple cubic structure, electron energy zone splits into two allowed energy bands and forbidden energy gap appears. In contrast to continual energy zone of allowed electron states in bulk crystals, the energy spectra in ultrathin films are discrete. The number of possible energy levels is equal to the double number of film layers along bounded direction. The influence of perturbation energy parameters on electron energy spectra was also analyzed. Increase in electron energy at the surfaces induces a shift of the spectrum towards higher energies. The width of forbidden energy gap has the highest value, when electron surface energies are not perturbed. With increase in transfer energy of electrons at the surfaces the spectrum broadens, while the width of forbidden gap decreases. Determination of the electron space distribution has shown the existence of localized states. Varying the boundary conditions it is possible to induce appearance of energy gaps inside the spectra (the allowed energy bands of thin film become narrower than those of the bulk) or appearance of localized states (lying outside the bulk limits). Addresses: Fac Sci, Inst Phys, Novi Sad, Yugoslavia; Fac Med, Banja Luka, Bosnia & Herceg; Univ Politehn Timisoara, Timisoara, Romania Reprint Address: Setrajcic, JP, Fac Sci, Inst Phys, Novi Sad, Yugoslavia. ISSN: ISBN: Record 21 of 31 ; Jacimovski, SK; Tosic, BS; Setrajcic, JP

9 9 of :27 Title: Kinetics of thin films mechanical oscillations Source: PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, 317 (1-2): JAN Author Keywords: thin films; phonons; mean-square displacements; specific heat; thermal conductivity KeyWords Plus: ULTRATHIN LAYERED STRUCTURES; PHONONS Abstract: Thermal conductivity of thin film is analyzed in this paper. It has been shown that at low temperatures, thermal conductivity of film is considerably lower than that of bulk structure. Also, the dependence of activation energy on boundary conditions has been investigated. It has been found that the implantation of light molecules in film boundaries leads to considerably higher activation temperatures. Our theoretical results proved to be in agreement with some of the latest experimental data. (C) 2002 Elsevier Science B.V. All rights reserved. Addresses: Univ Novi Sad, Fac Sci, Inst Phys, YU Novi Sad, Yugoslavia; Univ Politehn Timisoara, Timisoara 1900, Romania; D Obradovic High Sch, YU Novi Knezevac, Yugoslavia Reprint Address: Setrajcic, JP, Univ Novi Sad, Fac Sci, Inst Phys, Trg D Obradovica 4, YU Novi Sad, Yugoslavia. Times Cited: 7 ISSN: Record 22 of 31 Title: New coherent states for the BDS-Hamiltonian Source: CZECHOSLOVAK JOURNAL OF PHYSICS, 52 (9): SEP 2002 Author Keywords: coherent states; density matrix KeyWords Plus: SQUEEZED STATES; OSCILLATOR Abstract: In the paper we construct a new set of coherent states for a deformed Hamiltonian of the harmonic oscillator, previously introduced by Beckers, Debergh, and Szafraniec, which we have called the BDS-Hamiltonian. This Hamiltonian depends on the new creation operator a(lambda)(+), i.e. the usual creation operator displaced with the real quantity lambda. In order to construct the coherent states, we use a new measure in the Hilbert space of the Hamiltonian eigenstates, in fact we change the inner product. This ansatz assures that the set of eigenstates be orthonormalized and complete. In the new inner product space the BDS-Hamiltonian is self-adjoint. Using these coherent states, we construct the corresponding density operator and we find the P-distribution function of the unnormalized density operator of the BDS-Hamiltonian. Also, we calculate some thermal averages related to the BDS-oscillators system which obey the quantum canonical distribution conditions. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Regina Maria 1,Of Postal 5, Timisoara 1900, Romania. ISSN: Record 23 of 31 Title: Photon-added Barut-Girardello coherent states of the pseudoharmonic oscillator Source: JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, 35 (33): AUG KeyWords Plus: SPECTRUM GENERATING ALGEBRA; HARMONIC OSCILLATOR; BEAM SPLITTER; NUMBER Abstract: In a previous paper (Popov D 2001 J. Phys. A: Math. Gen ) we have constructed the coherent states (CSs) of the pseudoharmonic oscillator (PHO). These states are of the Barut-Girardello type. In the present paper, we have constructed and investigated some properties of the photon-added Barut-Girardello coherent states (PA-BGCSs) of the PHO. These states are not orthogonal but are normalized and satisfy a unity resolution relation (the completeness relation). We have found the analytical form for the positive weight function in the resolution of unity. By using these states, we have calculated some expectation values (the first two powers of the number operator N), which have evinced some non-classical properties. In order to examine the statistical properties of a PHO gas, which obeys the quantum canonical distribution, the diagonal P-representation of the density operator P (I) is constructed and the thermal expectation values are calculated. All these quantities are expressed in terms of Meijer G-functions, and so the PA-BGCSs are a new field of application for these functions. Also, the time dependence of the PA-BGCSs is examined. If in the obtained results we put m = 0, we recover all the results from our previous paper. Addresses: Univ Politehnica Timisoara, Dept Phys, R-1900 Timisoara, Romania Reprint Address: Popov, D, Univ Politehnica Timisoara, Dept Phys, Piata Regina Maria 1,Of Postal 5, R-1900 Timisoara, Romania. Times Cited: 8

10 10 of :27 ISSN: Record 24 of 31 Title: Barut-Girardello coherent states of the pseudoharmonic oscillator Source: JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, 34 (25): JUN KeyWords Plus: PHOTON STATES; POTENTIALS; ALGEBRA; SU(1 Abstract: In the paper we have investigated some properties off the Barut-Giraradello coherent states (BGCS) (the eigenstates of the SU(1, 1) lowering generator K_) for the Hamiltonian of the pseudoharmonic oscillator (PHO). By using these states, the diagonal P-representation of the density operator is constructed as a new result for this potential. In addition, we have calculated some thermal expectation values for the quantum canonical gas of the PHOs. The calculations using the BGCS representation seem to be much simpler and easier to program than the corresponding calculations in other representations (e.g. the position representation). At the end of the paper the time dependence of these states is presented. Addresses: Univ Politehnica Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehnica Timisoara, Dept Phys, Piata Regina Maria 1,Of Postal 5, Timisoara 1900, Romania. Times Cited: 22 ISSN: Record 25 of 31 Title: Considerations concerning the harmonic limit of the Morse oscillator Source: PHYSICA SCRIPTA, 63 (4): APR 2001 KeyWords Plus: MATRIX-ELEMENTS; STATES Abstract: The comprehensive conditions concerning the harmonic limit of the Morse oscillator are investigated in this paper. These conditions extend the over-simple "classical" condition, which results by truncating the expansion of the Morse potential function in the power series of the coordinate close to the equilibrium position. The validity of the obtained results is tested by calculating the harmonic limit of the expected values of some characteristic physical observables of the Morse oscillator systems. Addresses: Univ Politehn Timisoara, Dept Phys, RO-1900 Timisoara, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Regina Maria 1, RO-1900 Timisoara, Romania. Times Cited: 7 ISSN: Record 26 of 31 Title: Density matrix theory for the BDS-Hamiltonian Source: INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS, 40 (4): APR 2001 KeyWords Plus: STATES; EXTENSION Abstract: In the present paper, we have extended the usual uncertainty relations, as well as the entropic uncertainty relations to the mixed states, particularly to the thermal states, using the density matrix formalism. As quantum model we have choosen the quantum mechanical ideal gas with the harmonic oscillator-like Hamiltonian H-lambda, introduced by Beckers, Debegh and Szafraniec, generically named BDS-Hamiltonian. Addresses: Univ Politech Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politech Timisoara, Dept Phys, Piata Regina Maria 1,Of Postal 5, Timisoara 1900, Romania. Times Cited: 1 ISSN: Record 27 of 31 Author(s): Tosic, BS; Popov, D Title: A method for solving Bloch equation for Morse potential Source: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 61 (10): OCT 2000

11 11 of :27 Author Keywords: Bloch equation; Morse potential; internuclear potential Abstract: A method is presented for solving the Bloch equation for Morse potential, based on the application of Fourier transformation of the density matrix. The results obtained agree completely with the results obtained by other methods, however its advantage lies in its elegance and intuitivity of the approach. (C) 2000 Elsevier Science Ltd. All rights reserved. Addresses: Fac Sci Novi Sad, Inst Phys, YU Novi Sad, Yugoslavia; Univ Politehnica Timisoara, Catedra Fiz, Timisoara 1900, Romania Reprint Address: Popov, D, Fac Sci Novi Sad, Inst Phys, Trg Dositeja Obradovica 4, YU Novi Sad, Yugoslavia. Times Cited: 5 ISSN: Record 28 of 31 Title: Extension of the uncertainty relations to the mixed states Source: CZECHOSLOVAK JOURNAL OF PHYSICS, 49 (8): AUG 1999 KeyWords Plus: MORSE Abstract: In this paper we have extended the uncertainty relations to mixed states for some special cases of quantum oscillators, relations which are calculated for this kind of states by means of the earlier established virial and Hellmann-Feynman theorems. The lower bound of these uncertainty relations is estimated for a few exactly solvable potentials, too. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Horatiu 1, Timisoara 1900, Romania. Times Cited: 3 ISSN: Record 29 of 31 Title: Construction of the Green's function for the pseudoharmonical oscillator Source: CZECHOSLOVAK JOURNAL OF PHYSICS, 49 (2): FEB 1999 KeyWords Plus: MORSE Abstract: In the present paper we have constructed the Green's function for the pseudoharmonical potential, which is considered as an intermediate potential between the harmonic and anharmonic potentials. We have used a hybrid method, by combining the Laplace transformation method and the Green's function technique. The Green's function is used for obtaining the density matrix for a quantumstatistical system, in coordinate representation. Even if this is not a new result, the method can be applied to a class of exactly solvable potentials. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Horatiu 1, Timisoara 1900, Romania. ISSN: Record 30 of 31 Title: Extension of the quantum virial and Hellmann-Feynman theorems to the quantum statistical averages Source: INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, 69 (2): AUG Author Keywords: quantum virial theorem; Hellmann-Feynman theorem; density matrix; thermal states; pseudoharmonical oscillator Abstract: In the present article, we extended the quantum virial and Hellmann-Feynman theorems to the quantum statistical averages, that is, to the thermal states. We obtained some new formulas which make possible expressing the thermodynamical observables of the system as functions of the moments of coordinates, as we see in a short example relating to the pseudoharmonical oscillator. (C) 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: , Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Horatiu 1, Timisoara 1900, Romania. Times Cited: 4

12 12 of :27 ISSN: Record 31 of 31 Title: Coherent states of the pseudoharmonical oscillator Source: ACTA PHYSICA SLOVACA, 48 (1): 1-12 FEB 1998 Abstract: For the pseudoharmonical oscillator we hart built the creation and annihilation operators and the corresponding coherent states. After the deduction of the density operator expression in coherent-state reprsentation in two ways (by their definition and by solving the Bloch, equation), we have calculated the expected values of some characteristical physical observables. Addresses: Univ Politehn Timisoara, Dept Phys, Timisoara 1900, Romania Reprint Address: Popov, D, Univ Politehn Timisoara, Dept Phys, Piata Horatiu 1, Timisoara 1900, Romania. Times Cited: 3 ISSN: ISI Web of Knowledge Page 1 (Articles ) [ 1 ] Acceptable Use Policy Copyright 2008 Thomson Reuters