| 1. |
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| 2. |
- Klein, SR, et al.
(author)
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Does particle decay cause wave function collapse: an experimental test
- 2003
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In: Physics Letters. Section A: General, Atomic and Solid State Physics. - 0375-9601. ; 308:5-6, s. 323-328
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Journal article (peer-reviewed)abstract
- We describe an experimental test of whether particle decay causes wave function collapse. The test uses interference between two well separated, but coherent, sources of vector mesons. The short-lived mesons decay before their wave functions can overlap, so any interference must involve identical final states. Unlike previous tests of non-locality, the interference involves continuous variables, momentum and position. Interference can only occur if the wave function retains amplitudes for all possible decays. The interference can be studied through the transverse momentum spectrum of the reconstructed mesons.
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| 3. |
- Xu, Hongxing
(author)
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A new method by extending Mie theory to calculate local field in outside/inside of aggregates of arbitrary spheres
- 2003
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In: Physics Letters. Section A: General, Atomic and Solid State Physics. - 0375-9601. ; 312:5-6, s. 411-419
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Journal article (peer-reviewed)abstract
- In this Letter we describe a new method to combine the methods of matrix inversion and order-of-scattering to solve the light scattering of aggregates of arbitrary spheres by extending Mie theory, which is more expedient for calculations of the local field in both outside and inside of the spheres. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 4. |
- Basylko, S. A., et al.
(author)
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Coulomb glass in the restricted random phase approximation
- 2002
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 298:06-maj, s. 416-421
-
Journal article (peer-reviewed)abstract
- A three-dimensional model of N/2 electrons localized on N randomly distributed donor sites of density n and with the acceptor charge uniformly smeared on these sites, -e/2 on each. has been considered in the restricted random phase approximation (RRPA) which uses the set of 3N Fourier components of the local charge density as the independent collective variables. The energy e(T) per site and the density of one-site excitation energy (DOSE) g(epsilon) are shown to he, respectively, in excellent quantitative and in good qualitative agreement with the Monte Carlo simulation data in the whole temperature region 0.1 < T < 100, where these simulations were performed (e(2)n(1/3)/k(B) being the temperature scale). The pair correlator for the one-site energies g(epsilon,+/-epsilon, r) is found to have the slow decoupling law similar to(+/-1/r) for T less than or similar to 1 and r much greater than r(d) (r(d), Debye screening radius). The status of the commonly accepted asymptotic g(epsilon) similar to (epsilon - mu)(d-1) (d and mu being, respectively, the spatial dimension and the Fermi energy) is discussed. The deduction of this asymptotic is shown to be based on the strong and questionable conjecture about decoupling of correlations between one-site excitation energies in the vicinity of mu.
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| 5. |
- Basylko, S. A., et al.
(author)
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Ground-state study of a donor-acceptor model with finite charge-transfer energy
- 2000
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 271:02-jan, s. 134-138
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Journal article (peer-reviewed)abstract
- A donor-acceptor model with randomly distributed N donor and N acceptor sites and with finite charge transfer energy Delta is investigated at zero temperature by means of computer simulations on two-dimensional samples of different sizes, We demonstrate that the density of one-electron excitations g(epsilon) for accepters in the vicinity of the Fermi energy mu depends essentially on the size of the sample investigated and that g(epsilon) further away from mu exhibits a size-independent power-law with the non-universal exponent decreasing with increasing Delta. Rigorous relations for mu and for the mapping of g(epsilon) for donors into g(epsilon) for accepters are also given.
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| 6. |
- Bonnaud, Etienne L., et al.
(author)
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Inertia and damping effects on the damage-dependent burst size distribution of fiber bundles
- 2001
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 290, s. 261-269
-
Journal article (peer-reviewed)abstract
- Distributions of simultaneous fiber failures—bursts—in loaded fiber bundles are studied considering inertia and damping. Resulting burst size distributions have universal properties: all approach the power law DΔΔ−2.5 for larger burst sizes Δ. Momentary burst size distributions evolve with increasing damage and do not follow power laws but are still universal. Finally, it is briefly outlined how to use distribution progression to assess damage state.
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| 7. |
- Dyakonov, V., et al.
(author)
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Spin-wave resonance in the La0.7Mn1.3O3-delta film
- 2000
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 268:3, s. 202-207
-
Journal article (peer-reviewed)abstract
- The spin-wave resonance (SWR) spectra have been observed in the (001) oriented La0.7Mn1.3O3-delta epitaxial films. The spectra consist of a series of well-resolved spin-wave modes clearly seen in the: perpendicular external field configuration. It is shown that the spins are completely pinned on both sides of the film surface. Based on a study of the SWR spectra the value of the spin-wave exchange constant, D, is found to be 150 meV Angstrom(2). This value of. D correlates well with this one determined for all known until now manganites.
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| 8. |
- Ericsson, Marie, et al.
(author)
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Quantum computation using the Aharonov-Casher set up
- 2002
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 303:1, s. 7-10
-
Journal article (peer-reviewed)abstract
- It is argued that the Aharonov-Casher set up could be used as the basic building block for quantum computation. We demonstrate explicitly in this scenario one- and two-qubit phase shift gates that are fault tolerant to deformations of the path when encircling two sites of the computational system around each other.
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| 9. |
- Fasoli, A., et al.
(author)
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Isotope mass scaling of AE damping rates in the JET tokamak plasmas
- 2000
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 265:4, s. 288-293
-
Journal article (peer-reviewed)abstract
- The damping of radially extended Alfven eigenmodes in tokamak plasmas is investigated in JET discharges with different ion mass. The comparison of damping measurements with predictions of a gyro-kinetic model indicates that mode conversion into kinetic Alfven waves is the dominant damping mechanism for Alfven eigenmodes in the plasma core.
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| 10. |
- Ghiu, I., et al.
(author)
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Entanglement-assisted local transformations between inequivalent classes of three-particle entangled states
- 2001
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 287:02-jan, s. 12-18
-
Journal article (peer-reviewed)abstract
- We show that bipartite and tripartite entangled states cannot be used as catalysis states to enable local transformations inbetween inequivalent classes of three-particle entangled states which are non-interchangeable under local transformations. We find the optimal protocol for conversion of a certain family of the W-states and an EPR-pair into the GHZ-state.
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| 11. |
- Kundrotas, P. J., et al.
(author)
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Coulomb correlation gap : Finite-size analysis
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 287:04-mar, s. 278-282
-
Journal article (peer-reviewed)abstract
- A semiclassical model with randomly distributed N donor and K x N acceptor sites and with infinite-range Coulomb interaction is investigated by means of computer simulations on two-dimensional samples of different sizes. The shape of the Coulomb correlation gap in the density of one-electron excitations g(epsilon) is obtained for different values of K within a wide energy interval around the Fermi energy mu. Using simple scaling arguments we demonstrate that the true behavior of g(epsilon) in the immediate neighborhood of mu is hidden by the finite-size effects and find that g(epsilon) further away from mu is described by a power-law with an exponent, depending on K and the sign of epsilon - mu.
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| 12. |
- Larsson, Peter, et al.
(author)
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Noncyclic mixed state phase in SU(2) polarimetry
- 2003
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 315:1-2, s. 12-15
-
Journal article (peer-reviewed)abstract
- We demonstrate that Pancharatnam's relative phase for mixed spin-1/2 states in noncyclic SU(2) evolution can be measured polarimetrically.
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| 13. |
- Qiu, Min, et al.
(author)
-
FDTD algorithm for computing the off-plane band structure in a two-dimensional photonic crystal with dielectric or metallic inclusions
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 278:6, s. 348-354
-
Journal article (peer-reviewed)abstract
- An effective numerical method based on the finite-difference time-domain scheme for computing the off-plane band structure of a two-dimensional photonic crystal is presented. The method is an order N method, and requires only a two-dimensional discretization mesh for a given off-plant wave number k(z) although thr off-plane propagation is a three-dimensional problem. The computation time and memory required is thus reduced significantly. The present method can be used for any type of inclusions and no additional effort is needed for metallic inclusions. The off-plane band structures of a square lattice of metallic rods in the air are studied, and a complete bandgap for some nonzero off-plane wave number k(z) is found.
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| 14. |
- Qiu, Min, et al.
(author)
-
Guided modes in a two-dimensional metallic photonic crystal waveguide
- 2000
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In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 266:4-6, s. 425-429
-
Journal article (peer-reviewed)abstract
- Guided modes in a two-dimensional metallic photonic crystal waveguide are studied. The guided modes in the photonic crystal waveguide are related to those in a conventional metallic waveguide. There exists a cutoff frequency and consequently a mode gap at low frequencies (starting from zero frequency) in the photonic crystal metallic waveguide.
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| 15. |
- Qiu, Min, et al.
(author)
-
Surface modes in two-dimensional dielectric and metallic photonic band gap structures : a FDTD study
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 282:1-2, s. 85-91
-
Journal article (peer-reviewed)abstract
- In the present Letter, surface modes in two-dimensional dielectric and metallic photonic crystals are studied by a finite-difference time-domain method. The existence of surface modes in metallic photonic crystals is examined. The influence of surface waves on dielectric photonic crystal antennas is also studied.
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| 16. |
- Raadu, Michael A., et al.
(author)
-
Test charge response of a dusty plasma with a grain size distribution
- 2002
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 305, s. 79-86
-
Journal article (peer-reviewed)abstract
- The form of the grain size distribution strongly influences the linear dielectric response of a dusty plasma. For a class of size distributions there is an equivalence to a Lorentzian distribution of mono-sized particles. The electrostatic response to a slowly moving test charge, using a second order approximation, is found. The effects of collisions are investigated.
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| 17. |
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| 18. |
- Shukla, Padma, et al.
(author)
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Excitation of zonal flows by electron convective cells in a nonuniform dusty magnetoplasma
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 283:5-6, s. 371-375
-
Journal article (peer-reviewed)abstract
- It is shown that the ponderomotive force of electron convective cells can generate zonal flows (or dust convective cells) in a nonuniform magnetoplasma. For this purpose, two fluid equations are used to derive a pair of coupled equations which govern the nonlinear coupling between electron and dust convective cells. A dispersion relation for the parametric interactions is deduced from the mode coupling equations. Explicit expressions for the growth rates of electron convective cell driven zonal flows are then obtained. The relevance of our investigation to laboratory and space plasmas is pointed out.
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| 19. |
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| 20. |
- Sjöqvist, Erik
(author)
-
Anandan–Aharonov–Casher oscillations in a simply connected region
- 2000
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 270:1-2, s. 10-13
-
Journal article (peer-reviewed)abstract
- An entanglement effect between the spin and spatial degrees of freedom of an electrically neutral spin-1/2 particle in a planar electric field is predicted. This nonclassical effect is manifested as spatial interference oscillations in a force free simply connected region of space. It is suggested that these oscillations provide an experimentally accessible analogue of Anandan's "quantum solenoid effect'' [Phys. Lett. A 164 (1992) 369], The effect could be tested with spin polarised atoms.
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| 21. |
- Sjöqvist, Erik
(author)
-
Proposed interferometry test of noncyclic geometric phase
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 286:1, s. 4-6
-
Journal article (peer-reviewed)abstract
- An interferometric test of the geometric phase in noncyclic spin-1/2 precession is proposed. It is shown that the resulting interference shift depends only on the noncyclic geometric phase for any opening angle on the Bloch sphere as well as for any degree of polarisation.
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| 22. |
- Tracy, E. R., et al.
(author)
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A ray-based algorithm for multi-dimensional linear conversion
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 290:06-maj, s. 309-316
-
Journal article (peer-reviewed)abstract
- A numerical algorithm is proposed for connecting the incoming and outgoing wave fields in studies of linear conversion. This is the first such ray-based algorithm for wave conversion in multiple spatial dimensions. It is demonstrated that, aside from the overall phase of the coupling, one can directly evaluate all quantities needed for the connection coefficients from the ray geometry. The ray dynamics is generated using the determinant of the dispersion matrix as the Hamiltonian. Using information available while following an incoming ray, the algorithm automatically detects that the ray has entered a conversion region, evaluates the transmission and conversion coefficients, and launches the transmitted ray. The algorithm does not require any prior knowledge of the geometry of the conversion region. The algorithm is illustrated using a two-dimensional toroidal model with resonant conversion from a magnetosonic to an ion-hybrid wave.
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| 23. |
- Voloshin, V. A., et al.
(author)
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Interplay of structure, magnetism and resistivity of La0.5Ca0.54MnO3+x
- 2000
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 271:02-jan, s. 121-127
-
Journal article (peer-reviewed)abstract
- The structure of La0,5Ca0,5MnO3 is well known for T> 250 K and T( 150 K. But in the intermediate region some structure characteristics are difficult to understand [1]. This Letter studies in this temperature region the interrelation between structure and the experimental data like magnetism and resistivity on the basis of a vibron-electron dynamic equilibrium hypothesis. It has been shown that behavior of paramagnetic-to-ferromagnetic transition can be explaned in the framework of this hypothesis.
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| 24. |
- Wiklund, Krister, et al.
(author)
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Hermitian structure for linear internal waves in sheared flow
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 279:1-2, s. 67-69
-
Journal article (peer-reviewed)abstract
- Motivated by the problem of linear mode conversion between ducted internal gravity waves in a sheared flow, we construct a variational principle based on a Hermitian evolution operator, obtained from Larsson's Hamiltonian formalism.
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| 25. |
- Wiklund, Krister, et al.
(author)
-
Mode coupling and stability of modified convective cells in a nonuniform dusty magnetoplasma
- 2001
-
In: Physics Letters A. - 0375-9601 .- 1873-2429. ; 279:3-4, s. 239-242
-
Journal article (peer-reviewed)abstract
- Within the framework of a Hamiltonian approach, we study mode coupling and stability of nonlinearly interacting modified convective cells in a nonuniform dusty magnetoplasma. Expressions for the coupling coefficients and a stability criterion for the stationary solutions are presented. This is a necessary prerequisite for understanding the nonlinear dynamics of convective cells in a dusty magnetoplasma with a strongly nonuniform background.
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| 26. |
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| 27. |
- Zhao, QX, et al.
(author)
-
Nonradiative centers in InAs dots grown on GaAs substrates for 1.3 mu m emission
- 2003
-
In: Physics Letters A. - : Elsevier Science B.V., Amsterdam.. - 0375-9601 .- 1873-2429. ; 315:02-Jan, s. 150-155
-
Journal article (peer-reviewed)abstract
- Nonradiative centers in InAs dots grown on GaAs substrates are investigated in this study. The emission from InAs dots close to 1.3 mum is monitored under different excitation densities and different excitation energy. The used samples were also treated by hydrogen plasma in order to suppress the nonradiative centers. The purpose of this work is to study how nonradiative centers influence the efficiency of InAs dots emission and whether the nonradiative centers can be reduced. Our results clearly illustrate that there indeed exist nonradiative centers, both at the interface between the InAs dots and surrounding layers and in the GaAs layers, which can be suppressed by H-treatments. A technique to estimate relative amount of nonradiative centers is also discussed.
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| 28. |
- Abdelsalam, UM, et al.
(author)
-
Ion-acoustic solitary waves in a dense pair-ion plasma containing degenerate electrons and positrons
- 2008
-
In: Physics Letters A. - Amsterdam : Elsevier. - 0375-9601 .- 1873-2429. ; 372:22, s. 4057-4061
-
Journal article (peer-reviewed)abstract
- Fully nonlinear propagation of ion-acoustic solitary waves in a collisionless dense/quantum electron-positron-ion plasma is investigated. The electrons and positrons are assumed to follow the Thomas-Fermi density distribution and the ions are described by the hydrodynamic equations. An energy balance-like equation involving a Sagdeev-type pseudo-potential is derived. Finite amplitude solutions are obtained numerically and their characteristics are discussed. The small-but finite-amplitude limit is also considered and an exact analytical solution is obtained. The present studies might be helpful to understand the excitation of nonlinear ion-acoustic solitary waves in a degenerate plasma such as in superdense white dwarfs.
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| 29. |
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| 30. |
- Ali, S, et al.
(author)
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Wake potential with mobile positive/negative ions in multicomponent dusty plasmas
- 2008
-
In: Physics Letters A. - Amsterdam : Elsevier. - 0375-9601 .- 1873-2429. ; 372:44, s. 6650-6652
-
Journal article (peer-reviewed)abstract
- We employ the test charge approach to calculate the electrostatic potential for a test charge in a multicomponent dusty plasma, whose constituents are the Boltzmann distributed electrons, mobile positive and negative ions, and immobile positive/negative charged dust particles. By using the modified dielectric constant of the dust-ion-acoustic (DIA) waves, the Debye screening and wake potentials are obtained. It is found that the presence of mobile negative ions significantly modify the DIA speed and the wake potential. The present results are relevant to polar mesosphere and microelectronic in the context of charged particle attraction and repulsion.
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| 31. |
- Allaoui, Aissa, et al.
(author)
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On the compressive response of carbon nanotube tangles
- 2009
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 373:35, s. 3169-3173
-
Journal article (peer-reviewed)abstract
- The nonlinear bulk compressibility of entangled multiwalled carbon nanotubes is studied. The analogy with textile fibre assemblies is explored by means of the well established van Wyk model. In view of the small diameter of the nanotubes. the possible effect of adhesive van der Waals interactions at tube-tube contacts is analysed. It is found, however, that the contribution of adhesive contacts to the bulk stress should be negligible. Compression experiments are performed on multi-walled carbon nanotubes and show that van Wyk's model is able to describe the response, although the values of the dimensionless parameter k of van Wyk's model were lower than expected. There is indeed no indication that van der Waals interactions play any significant role.
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| 32. |
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| 33. |
- Badiei, Shahriar, 1969, et al.
(author)
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Laser initiated detonation in Rydberg matter with a fast propagating shock wave, releasing protons with keV kinetic energy
- 2005
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In: Physics Letters A. - : Elsevier BV. - 0375-9601. ; 344:2-4, s. 265-270
-
Journal article (peer-reviewed)abstract
- Laser pulses of 50 mJ energy initiate detonations that release energy and create shock waves in a phase of Rydberg matter (RM) mainly consisting of H-2 RM clusters. The shock wave has a speed of approximately 20 km s(-1). It is observed in coupled angular and time-of-flight distributions of charges released. The high speed of the shock indicates that RM is a condensed material. The kinetic energy of protons from hydrodynamic acceleration is > 1 keV. Protons are also released directly in Coulomb explosions from the lowest energy state n = 1 of H RM, with energies of 9.4 and 19 eV. (c) 2005 Elsevier B.V. All rights reserved.
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| 34. |
- Badiei, Shahriar, 1969, et al.
(author)
-
Lowest state n=1 of H atom Rydberg matter: many eV energy release in Coulomb explosions
- 2004
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601. ; 327:2-3, s. 186-191
-
Journal article (peer-reviewed)abstract
- Neutral Rydberg species with well defined kinetic energy of 9.4 eV per unit mass are emitted from a cloud of Rydberg matter (RM) when a 5 ns laser pulse passes through it. The energy of 9.4 eV agrees with the energy relased at a principal quantum number n = 1 in RM. This level is expected in the RM form only for hydrogen atoms, and has not been observed previously. RM consisting partially of H atoms is now produced using a hydrogen gas pressure > 10(-6) mbar. (C) 2004 Elsevier B.V. All rights reserved.
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| 35. |
- Balazsi, G, et al.
(author)
-
From stochastic resonance to brain waves
- 2000
-
In: PHYSICS LETTERS A. - : ELSEVIER SCIENCE BV. - 0375-9601. ; 265:4, s. 304-316
-
Journal article (peer-reviewed)abstract
- Biological neurons are good examples of a threshold device - this is why neural systems are in the fetus when looking for realization of Stochastic Resonance (SR) and spatio-temporal stochastic resonance (STSR) phenomena. In this Letter a simple integrate
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| 36. |
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| 37. |
- Boswell, C. J., et al.
(author)
-
Observation and explanation of the JET n=0 chirping mode
- 2006
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 358:2, s. 154-158
-
Journal article (peer-reviewed)abstract
- Persistent rapid up and down frequency chirping modes with a toroidal mode number of zero (n = 0) have been observed in the JET tokamak when energetic ions, with a mean energy similar to 500 keV, were created by high field side ion cyclotron resonance frequency heating. This heating method enables the formation of an energetically inverted ion distribution function that allows ions to spontaneously excite the observed instability, identified as a global geodesic acoustic mode. The interpretation is that phase space structures form and interact with the fluid zonal flow to produce the pronounced frequency chirping.
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| 38. |
- Brodin, Gert, et al.
(author)
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Anomalous reflection and excitation of surface waves in metamaterials
- 2007
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 367:3, s. 233-236
-
Journal article (peer-reviewed)abstract
- We consider reflection of electromagnetic waves from layered structures with various dielectric and magnetic properties, including metamaterials. Assuming periodic variations in the permittivity, we find that the reflection is in general anomalous. In particular, we note that the specular reflection vanishes and that the incident energy is totally reflected in the backward direction, when the conditions for resonant excitation of leaking surface waves are fulfilled.
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| 39. |
- Brodin, Gert, et al.
(author)
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Kinetic and quantum electrodynamical theory for circularly polarized waves in a plasma
- 2007
-
In: Physics Letters A. - : Elsevier. - 0375-9601 .- 1873-2429. ; 371, s. 462-
-
Journal article (peer-reviewed)abstract
- The theory for large amplitude circularly polarized waves propagating along an external magnetic field is further developed. Relativistic effects, quantum electrodynamical effects due to vacuum polarization and magnetization, as well as kinetic effects are included in our formalism. A general dispersion relation, which unites previous results, is derived. As a specific example, a low-frequency kinetic mode with a detailed dependence on the electron distribution function is studied.
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| 40. |
- Buric, Nikola, et al.
(author)
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Entanglement in quantum integrable and chaotic systems with Markov dynamics
- 2009
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In: Physics Letters. Section A: General, Atomic and Solid State Physics. - : Elsevier BV. - 0375-9601. ; 373:17, s. 1531-1539
-
Journal article (peer-reviewed)abstract
- Entanglement evolution is studied in open systems represented by rings of qubits with the Ising interaction and variously oriented external field and with Markov environments. The effect of thermal or dephasing environment is manifested as exponential decrease of the entanglement superposed on its dynamics in the isolated system. (C) 2009 Elsevier B.V. All rights reserved.
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| 41. |
- Bychkov, Vitaly, 1968-, et al.
(author)
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The Rayleigh-Taylor instability and internal waves in quantum plasmas
- 2008
-
In: Physics Letters A. - Amsterdam : North-Holland. - 0375-9601 .- 1873-2429. ; 372:17, s. 3042-3045
-
Journal article (peer-reviewed)abstract
- Influence of quantum effects on the internal waves and the Rayleigh-Taylor instability in plasma is investigated. It is shown that quantum pressure always stabilizes the RT instability. The problem is solved both in the limit of short-wavelength perturbations and exactly for density profiles with layers of exponential stratification. In the case of stable stratification, quantum pressure modifies the dispersion relation of the inertial waves. Because of the quantum effects, the internal waves may propagate in the transverse direction, which was impossible in the classical case. A specific form of pure quantum internal waves is obtained, which do not require any external gravitational field.
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| 42. |
- Cai, Yangjian, et al.
(author)
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Propagation of various dark hollow beams through an apertured paraxial ABCD optical system
- 2006
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 357:1, s. 72-80
-
Journal article (peer-reviewed)abstract
- Propagation of a dark hollow beam (DHB) of circular, elliptical or rectangular symmetry through an apertured paraxial ABCD optical system is investigated. Approximate analytical formulas for various DHBs propagating through an apertured paraxial optical system are derived by expanding the hard-aperture function into a finite sum of complex Gaussian functions in terms of a tensor method. Some numerical results are given. Our formulas provide a convenient way for studying the propagation of various DHBs through an apertured paraxial optical system.
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| 43. |
- Chang, CH, et al.
(author)
-
Spin transmission through quantum dots with strong spin-orbit interaction
- 2004
-
In: Physics Letters. Section A: General, Atomic and Solid State Physics. - : Elsevier BV. - 0375-9601. ; 326:5-6, s. 436-441
-
Journal article (peer-reviewed)abstract
- Quantum oscillations of the spin conductance through regular and chaotic 2D quantum dots under the varying Rashba spin-orbit interaction and at zero magnetic field have been investigated numerically by summing up the spin evolution matrices for classical transmitting trajectories. The Fourier analysis of these oscillations indicates a strong geometry dependence of the power spectra. The spectra for narrow rings are dominated by a single peak as previous analytic result, for regular quantum dots are represented by multiple peaks, and for chaotic quantum dots by quasi-continuum peaks.
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| 44. |
- Constantin, Adrian, et al.
(author)
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Integrability of invariant metrics on the Virasoro group
- 2006
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 350:1-2, s. 75-80
-
Journal article (peer-reviewed)abstract
- Each right-invariant metric on the Virasoro group induces a Hamiltonian vector field on the dual of the Lie algebra vir equipped with the canonical Lie-Poisson structure. We show that the Hamiltonian vector fields Xk induced by the metrics given at the identity by the Hk Sobolev inner products, k≥0, are bi-Hamiltonian relative to a modified Lie-Poisson structure only for k=0 and k=1.
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| 45. |
- Constantin, Adrian, et al.
(author)
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On an integrable two-component Camassa-Holm shallow water system
- 2008
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In: Physics Letters. Section A: General, Atomic and Solid State Physics. - : Elsevier BV. - 0375-9601. ; 372:48, s. 7129-7132
-
Journal article (peer-reviewed)abstract
- The interest in the Camassa-Holm equation inspired the search for various generalizations of this equation With interesting properties and applications. In this Letter we deal with such a two-component integrable system Of Coupled equations. First we derive the system in the context of shallow water theory. Then we show that while small initial data develop into global Solutions, for some initial data wave breaking Occurs. We also discuss the Solitary Wave Solutions. Finally, we present all explicit construction for the peakon Solutions in the short wave limit of system. (C) 2008 Elsevier B.V. All rights reserved.
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| 46. |
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| 47. |
- Deser, S, et al.
(author)
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Clebsch (string) decomposition in d=3 field theory
- 2001
-
In: PHYSICS LETTERS A. - : ELSEVIER SCIENCE BV. - 0375-9601. ; 279:3-4, s. 151-153
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Journal article (peer-reviewed)abstract
- We study the applicability of the intrinsically nonlinear Clebsch vector field decomposition into three scalars in the description of d = 3 field theories. In particular, we note and account for the incompleteness of this parameterization when attempting
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| 48. |
- El-Taibany, WF, et al.
(author)
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On the instability of electrostatic waves in a nonuniform electron-positron magnetoplasma
- 2008
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In: Physics Letters A. - Amsterdam : Elsevier. - 0375-9601 .- 1873-2429. ; 372:22, s. 4067-4075
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Journal article (peer-reviewed)abstract
- The dispersion properties of three-dimensional electrostatic waves in a nonuniform electron-positron (EP) magnetoplasma are analyzed. A new dispersion relation is derived by use of the electron and positron density responses arising from the electron and positron continuity and Poisson equations. In the local approximation, the dispersion relation admits two wave modes with different velocities. The growth rates of various modes are illustrated both analytically and numerically. Considering the temperature gradients produces a linearly stable transverse mode. The growth rate of the slow mode instability due to the density inhomogeneity only is the highest one, though it appears at higher thermal energy. The angle of the wave propagation affects drastically on the instability features in each case. The applications of the present analysis are briefly discussed.
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| 49. |
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| 50. |
- Ericsson, Marie, et al.
(author)
-
Nodal free geometric phases : concept and application to geometric quantum computation
- 2008
-
In: Physics Letters A. - : Elsevier BV. - 0375-9601 .- 1873-2429. ; 372:5, s. 596-599
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Journal article (peer-reviewed)abstract
- Nodal free geometric phases are the eigenvalues of the final member of a parallel transporting family of unitary operators. These phases are gauge invariant, always well defined, and can be measured interferometrically. Nodal free geometric phases can be used to construct various types of quantum phase gates.
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