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Showing papers in "Physics Letters A in 1989"


Journal ArticleDOI
TL;DR: In this article, the properties of optical resonators with quality-factor Q⩾108, effective volume of e.m. field localization Veff ≥ 10−9 cm3 and threshold power of optical bistability Wbist≈10−5 W are described.
Abstract: The properties of optical resonators with quality-factor Q⩾108, effective volume of e.m. field localization Veff≈10−9 cm3 and threshold power of optical bistability Wbist≈10−5 W are described. The prospects to reduce Veff and Wbist are discussed. With possible reduction of controlling energy of optical switching down to a single quantum and employment of the monophotonic states of light, the whispering-gallery microresonators can open the way to realize Feynman's quantum-mechanical computer.

791 citations


Journal ArticleDOI
TL;DR: In this article, a two-dimensional (2D) lattice model of hexagonal molecules on a triangular lattice interacting via a nearest-neighbour n -inverse-power site-site potential is shown to display an anomalous (negative) Poisson ratio at high densities when the anisotropy (nonconvexity) of the molecules is substantial.
Abstract: A two-dimensional (2D) lattice model of hexagonal molecules on a triangular lattice interacting via a nearest-neighbour n -inverse-power site-site potential is shown to display an anomalous (negative) Poisson ratio at high densities when the anisotropy (non-convexity) of the molecules is substantial. It is suggested that such a behaviour may be observed in some real systems.

453 citations


Journal ArticleDOI
TL;DR: In this paper, a new algorithm is used to determine fractal dimensions by box counting for dynamic and iterated function systems, which is fast, accurate, and less dependent on data specific curve fitting criteria than the correlation dimension.
Abstract: A new algorithm is used to determine fractal dimensions by box counting for dynamic and iterated function systems. This method is fast, accurate, and less dependent on data specific curve fitting criteria than the correlation dimension.

449 citations


Journal ArticleDOI
TL;DR: In this article, the interaction geometry comprising four travelling laser waves which is used to obtain optical Ramsey fringes in atomic spectroscopy, is also well suited to build an atom interferometer based on the atomic recoil.
Abstract: It is shown that the interaction geometry comprising four travelling laser waves which is used to obtain optical Ramsey fringes in atomic spectroscopy, is also well suited to build an atom interferometer based on the atomic recoil. Since two different internal states are associated with the two arms of the interferometer, the de Broglie phase, induced by rotation or acceleration, manifests itself as a frequency shift of the Ramsey fringes.

446 citations


Journal ArticleDOI
TL;DR: In this paper, the authors obtained nonstationary soliton-like solutions for an extended version of the classical massive Thirring model which, in nonlinear optics, describes Bragg-resonant wave propagation in a periodic Kerr medium.
Abstract: We obtain new nonstationary soliton-like solutions for an extended version of the classical massive Thirring model which, in nonlinear optics, describes Bragg-resonant wave propagation in a periodic Kerr medium. These solitons represent intense optical wavetrains whose envelope travels unchanged through a distributed feedback reflection filter, in spite of the fact that the mean wavelength of the soliton is in the center of the forbidden gap. The soliton group velocity may be anywhere between zero and the speed of light in the medium.

417 citations


Journal ArticleDOI
TL;DR: In this article, the long-term free evolution of wave packets formed by highly excited states of quantum systems performing regular periodic motion in the classical limit is considered, and the universal asymptotic scenario of the wave function temporal development is discovered which provides the generation of a certain sequence of initial wave packet fractional revivals.
Abstract: The long-term free evolution of wave packets formed by highly excited states of quantum systems performing regular periodic motion in the classical limit is considered. The universal asymptotic scenario of the wave function temporal development is discovered which provides the generation of a certain sequence of initial wave packet fractional revivals. Each revival represents the coherent superposition of macroscopically distinguishable quantum states. The manifestation of the phenomenon in the dynamics of a Rydberg atom excited by a short laser pulse is discussed.

412 citations


Journal ArticleDOI
TL;DR: In this article, the first minimum of the logarithm of the generalized correlation integral C1(τ) provides an easily evaluable criterion for the proper choice of the time delay τ that is needed to reconstruct the trajectory in phase space from chaotic scalar time series data.
Abstract: It is shown that the first minimum of the logarithm of the generalized correlation integral C1(τ) provides an easily evaluable criterion for the proper choice of the time delay τ that is needed to reconstruct the trajectory in phase space from chaotic scalar time series data.

310 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the dynamics of a tunnel junction with small capacitance and conductance biased by a voltage smaller than the Coulomb blockade threshold can be adequately described in terms of the macroscopic quantum tunneling of the electric range ( q -MQT).
Abstract: It is shown that the dynamics of a tunnel junction with small capacitance and conductance biased by a voltage smaller than the Coulomb blockade threshold can be adequately described in terms of the macroscopic quantum tunneling of the electric range ( q -MQT). The q -MQT rate is calculated for a single junction and for several multi-junction systems.

246 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the whole Painleve analysis of PDEs is invariant under an arbitrary homographic transformation of the function defining the singularity manifold.
Abstract: The whole Painleve analysis of PDEs is shown to be invariant under an arbitrary homographic transformation of the function ϕ defining the singularity manifold. The best expansion function is ϰ = ( ϕ x ϕ − ϕ xx 2ϕ x ) -1 . This solves the ques tion of invariance under the Mobius group in Painleve analysis and explains naturally Backlund transformation between solutions.

201 citations


Journal ArticleDOI
TL;DR: In this article, an algebraic method to construct an infinite number of exact solutions of the KP hierarchy in terms of the hodograph transform is presented, which can be also applied to any hydrodynamic type equations with additional symmetries.
Abstract: We give an algebraic method to construct an infinite number of exact solutions of the KP hierarchy in terms of the hodograph transform. These solutions are obtained from a unique decomposition of the matrices in the higher commuting flows. The method presented here can be also applied to any hydrodynamic type equations with additional symmetries.

179 citations


Journal ArticleDOI
TL;DR: The existence of bound states for the s-wave Klein-Gordon equation for vector and scalar Hulthen-type potentials is shown in this paper, provided that the potential size is large enough.
Abstract: The existence of bound states for the s-wave Klein-Gordon equation for vector and scalar Hulthen-type potentials is shown, provided that the potential “size” is large enough. The solution can be explicitly written down in terms of hypergeometric functions. The effects of strong coupling on the bound states are discussed.

Journal ArticleDOI
TL;DR: In this article, a stochastic model for continuous measurement in a quantum system is given, where the posterior dynamics, including a continuous collapse of the wave function, is described by a nonlinear wave equation.
Abstract: A stochastic model for nondemolition continuous measurement in a quantum system is given. It is shown that the posterior dynamics, including a continuous collapse of the wave function, is described by a nonlinear stochastic wave equation. For a particle in an electromagnetic field it reduces to the Schrodinger equation with extra imaginary stochastic potentials.

Journal ArticleDOI
TL;DR: In this article, the nonlinear Schrodinger (NS) and KdV equations are shown to be reductions of the self-dual Yang-Mills (SDYM) equations.
Abstract: The nonlinear Schrodinger (NS) and KdV equations are shown to be reductions of the self-dual Yang-Mills (SDYM) equations. A correspondence between solutions of the NS and KdV equations and certain holomorphic vector bundles on a complex line bundle over the Riemann sphere is derived from Ward's SDYM twistor correspondence. Remarkably the twistor correspondence generalizes to the NS and KdV hierarchies when complex line bundles of higher Chern class are used. We discuss solitons and inverse scattering.

Journal ArticleDOI
TL;DR: In this article, a new model of the internal DNA dynamics is proposed and the nonlinear dynamical equations are derived and some particular solutions of the equations are discussed, and a new method for solving the equations is proposed.
Abstract: A new model of the internal DNA dynamics is proposed. The nonlinear dynamical equations are derived and some particular solutions of the equations are discussed.

Journal ArticleDOI
TL;DR: In this paper, the phase shift in the interference of a magnetic or electric dipole due to the electromagnetic field is obtained relativistically and non-relativistically, and the force and torque on the particle are obtained in the classical limit.
Abstract: The phase shift in the interference of a magnetic or electric dipole due to the electromagnetic field is obtained relativistically and non-relativistically. This is analogous to the Aharonov-Bohm effect, but is richer because of its non-Abelian character. The force and torque on the particle are obtained in the classical limit. The field equations in the presence of the quantum dipole are obtained at low energy.

Journal ArticleDOI
TL;DR: In this article, the effect of internal reflection of the propagation of waves in strongly scattering media has been investigated, and it has been shown that for backscattering and for transmission through relatively thin slabs, internal reflection can be very strong.
Abstract: We treat the effect of internal reflection of the propagation of waves in strongly scattering media. The theory will be applied to the recently discovered phenomenon of coherent backscattering of light and to the time-dependent transport of light intensity in reflection and in transmission geometries. For backscattering and for transmission through relatively thin slabs the influence of internal reflection can be very strong. For transmission through relatively thick slabs the effect can be accounted for by renormalizing the diffusion coefficient with a length-scale dependent reduction factor.

Journal ArticleDOI
TL;DR: In this paper, a new solid state structure with random atomic arrangement was proposed for nanocrystalline materials, which is shown by means of EXAFS to exhibit a new stable solid state.
Abstract: Nanocrystalline materials are polycrystals with a typical crystallite diameter of 5 to 15 nm. They structurally consist of two components with comparable volume fractions: a crystalline component and a grain boundary component, which is shown by means of EXAFS to exhibit a new solid state structure with random atomic arrangement to exhibit a new solid state structure with random atomic arrange

Journal ArticleDOI
TL;DR: In this paper, even and odd coherent states are discussed and the change of these two effects and the amplitude-squared squeezing when the two states are displaced are studied. And the authors showed that the displaced even coherent state can exhibit amplitude-quare squeezing.
Abstract: Squeezing and antibunching effects of even and odd coherent states are discussed. We also studied the change of these two effects and the amplitude-squared squeezing when the two states are displaced. The displaced even coherent state can exhibit amplitude-squared squeezing.

Journal ArticleDOI
TL;DR: In this article, three dominating subsequences of diagrams in the correlation correction to amplitude are summed: screening of the electron-electron interaction, particle-hole interaction, and the iterations of the self-energy.
Abstract: Three dominating subsequences of diagrams in the correlation correction to amplitude are summed: screening of the electron-electron interaction, particle-hole interaction, and the iterations of the self-energy The result of the calculations is E1(6s–7s) = (091 ± 001) × 10−11ieaB(−Qw/N),Qw is the weak charge of the nucleus, N is the number of neutrons A recent experiment of Noecker et al and our calculation give the following value of the Weinberg angle: sin2θw=0226±0007 (exp)±0004 (theor)

Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis confirmed that MFM image interpretation can be performed in terms of point dipole probing provided that some experimental constraints are satisfied, and the validity of the criterion is demonstrated for various experimentally relevant examples.
Abstract: Image interpretation in magnetic force microscopy (MFM) requires detailed information about the internal microstructure of the ferromagnetic tip used for probing the surface microfield of a sample. Since these informations are generally not experimentally available, image interpretation is more speculative than rigorously quantitative at the present time. This theoretical analysis confirms by a simple criterion that MFM image interpretation can be performed in terms of point dipole probing provided that some experimental constraints are satisfied. The validity of the criterion is demonstrated for various experimentally relevant examples.

Journal ArticleDOI
TL;DR: In this paper, Hall voltages in a resistive superconducting state and in a normal state are shown to have opposite signs, which is explained by a flux vortex motion.
Abstract: Hall voltages VH in a resistive superconducting state and in a normal state are shown to have opposite signs. This is accounted for by a flux vortex motion. Current-voltage characteristics V∝Ia(T) near the transition with a characteristic Nelson-Kosterlitz jump in a(T) at T = Tc present the evidence for a Kosterlitz-Thouless (KT) transition, which may be explained by flux vortex unbinding inside the superconducting planes.

Journal ArticleDOI
TL;DR: In this article, it is shown that there is substantial bias in dimension calculations with small data sets and that the estimated error bars are a small fraction of the actual error bars, and two empirical equations are presented to model these phenomena.
Abstract: With respect to two simple models and various distributions of noise, it is shown that there is substantial bias in dimension calculations with small data sets. Some of the practical difficulties involved in dimension estimation are briefly discussed. It is shown that estimated error bars are a small fraction of the actual error bars. Two empirical equations are presented to model these phenomena. One of these equations can be used to make some modest improvements in estimating dimension with small data sets The second equation indicates a procedure to obtain a more accurate assessment of error bars. Two statistical tests for deciding whether a desired time series is from an attractor or not are aslo suggested.

Journal ArticleDOI
TL;DR: In this paper, the wavelet transform was applied for characterizing the geometrical complexity of two-dimensional fractal aggregates and demonstrated the structural self-similarity of Witten and Sander diffusion-limited aggregates.
Abstract: We apply the wavelet transform for characterizing the geometrical complexity of two-dimensional fractal aggregates. We illustrate the efficiency of this mathematical microscope to capture the local scaling properties of self-similar snowflake fractals. We report on the first unambiguous numerical evidence for the structural self-similarity of Witten and Sander diffusion-limited aggregates (DLA). We emphasize the wavelet transform to be readily applicable to experimental situations.

Journal ArticleDOI
Dennis Dieks1
TL;DR: In this paper, it is pointed out that such "solutions" are unsatisfactory as they stand, and must be supplemented by a new empirical interpretation of the formal state description of quantum mechanics.
Abstract: In the recent literature there have been several proposals to solve the quantum mechanical measurement problem by taking into account that in measurement interactions there are many unobserved degrees of freedom. Tracing out the unobserved degrees of freedom results in decoherence between components of the wave function. This effectively implies transition to a mixture, which is then taken to explain the “reduction of the wave packet”. It is here pointed out that such “solutions” are unsatisfactory as they stand, and must be supplemented by a new empirical interpretation of the formal state description of quantum mechanics.

Journal ArticleDOI
TL;DR: In this article, a procedure for obtaining ǫ(α) directly from the scaling of histograms of multifractal measures is presented, and applied to several measures arising in dynamical systems and fully developed turbulence.
Abstract: A procedure for obtaining ƒ(α) directly from the scaling of histograms of multifractal measures is presented, and is applied to several measures arising in dynamical systems and fully developed turbulence. The method works well when the scaling range is large, and useful statistical information on iso-α sets such as lacunarity can be obtained. However, if the available scaling range is small, corrections of second order become importance and bias the ƒ(α) curve obtained directly.

Journal ArticleDOI
TL;DR: In this article, it was shown that the superintegrable chiral Potts model which has zero momentum and is the ground state for small λ is not the ground states for λ = 1 by exhibiting a state of nonzero momentum whose eigen value crosses the zero momentum eigenvalue at a value of λ less than 1.
Abstract: We demonstrate that the state of the superintegrable chiral Potts model which has zero momentum and is the ground state for small λ is not the ground state for λ=1 by exhibiting a state of nonzero momentum whose eigenvalue crosses the zero momentum eigenvalue at a value of λ less than 1.

Journal ArticleDOI
TL;DR: In this article, a stochastic model for the continuous non-demolition observation of the position of a quantum particle in a potential field and a boson reservoir is given, and it is shown that the Gaussian wave packet evolving according to the posterior wave equation with a quadratic potential tends to the Gaussian stationary solution.
Abstract: A stochastic model for the continuous nondemolition observation of the position of a quantum particle in a potential field and a boson reservoir is given. It is shown that the Gaussian wave packet evolving according to the posterior wave equation with a quadratic potential tends to the Gaussian stationary solution.

Journal ArticleDOI
TL;DR: In this paper, three different Lax representations for the periodic relativistic Toda lattice are exhibited and the complete integrability of the system is also proven, and the Lax representation is shown to be complete.
Abstract: Three different Lax representations for the periodic relativistic Toda lattice are exhibited. The complete integrability of the system is also proven.

Journal ArticleDOI
TL;DR: In this article, it was shown that for the SU(2) coupled system, the spherically symmetric asymptotically flat solutions possessing a non-singular event horizon and non-zero color magnetic charge are Abelian.
Abstract: It is shown that for the Einstein-Yang-Mills SU(2) coupled system the spherically symmetric asymptotically flat solutions possessing a non-singular event horizon and non-zero color magnetic charge are effectively Abelian.

Journal ArticleDOI
TL;DR: In this paper, the thermal equilibrium number of solitons in DNA as a function of absolute temperature and the number of base pairs was calculated by modeling DNA as Toda lattice with parameters chosen to match experimentally measured properties of DNA.
Abstract: Here we calculate the thermal equilibrium number of solitons in DNA as a function of absolute temperature and the number of base pairs. This calculation is effected by modeling DNA as a Toda lattice with parameters chosen to match experimentally measured properties of DNA. We find that a significant number of solitons is generated at physiological temperature (310 K).