It is shown that the initial assumption in the article by L-A. Wu [Phys. Rev. A 53, 2053 (1996)] leads to inconsistencies, calling into question the results which follow.

Differential cross sections describing the correlated motion of three electrons in the nuclear Coulomb field during the complete photofragmentation of a four-body system, the lithium atom, are calculated. Two selection rules are derived and their operation illustrated. Two features, not present in the corresponding three-body case are emphasized, namely that the Wannier configuration, in contrast to the three-body photofragmentation of helium, is allowed. Second, the cross section to access certain spin-momentum configurations of the three particles is zero for an uncorrelated but finite for a correlated final state.

We have measured doubly differential electron emission for transfer ionization produced by 100-keV ${\mathrm{H}}^{+}$ impact on an Ar target. Data were obtained by measuring coincidences between electrons of selected energy and angle of emission with outgoing ${\mathrm{H}}^0$ projectiles. The measurements covered emission angles in the range of θ=0° to 160° and energies starting from 10 eV. We present a detailed discussion on the experimental conditions used and give a tentative interpretation of the main features observed.

We report temperature measurements of atoms trapped in a three-dimensional (3D) optical lattice, a well-defined laser-cooling situation that can be treated with currently available theoretical tools. We also obtain fluorescence spectra from a 3D optical lattice, from which we obtain quantitative information about the trapping atoms, including the oscillation frequencies, spatial localization, and a temperature, which is in good agreement with our direct measurements. For comparison we study a 1D lattice using the same atom (cesium).

We form a one-dimensional optical lattice for Cs atoms using light tuned a few thousand linewidths below atomic resonance. Atoms are selectively loaded into deeply bound states by adiabatic transfer from a superimposed, near-resonance optical lattice. This yields a mean vibrational excitation n-bar≈0.3 and localization Δz≈λ/20. Light scattering subsequently heats the atoms, but the initial rate is only of order ${10}^{\mathrm{-}3}$ vibrational quanta per oscillation period. Low vibrational excitation, strong localization, and low heating rates make these atoms good candidates for resolved-sideband Raman cooling.

We have directly observed the motion of Rydberg wave packets of cesium in a static electric field through their ionization by half-cycle electromagnetic field pulses. Both Kepler orbital motion as well as angular motion, i.e., the periodic change in orbit ellipticity due to angular momentum evolution, can be clearly seen. The latter has never been directly observed, because conventional photoionization and two-pulse optical interferometry experiments are only sensitive to dynamics near the ion core and not when the wave packet has a high angular momentum.

Losses from a cesium magneto-optical trap induced by fine-structure changing collisions have been measured directly by counting of fluorescence photons emitted at the ${\mathrm{D}}_1$ resonance line, with the trap lasers operating on the ${\mathrm{D}}_2$ resonance line. The absolute value of the fine-structure loss rate coefficient has been measured and its dependence on the hyperfine state occupation has been explored. These results provide a fundamental test for the theoretical descriptions of excited-state trap losses.

A compact generalization of the Keldysh ionization amplitude is derived that includes rescattering. It is used for calculations of above-threshold ionization spectra with respect to energy for various emission angles for tunneling ionization of helium at high intensity, for the simple case of a zero-range potential as the binding potential. Most of the essential features of recent measurements are reproduced, that is, the onset, the extent, and the relative height of the plateau, which makes up the major part of the observed spectrum.

We study the quantum evolution of Kaplan's nonlinear eigenmode for the degenerate parametric oscillator. We calculate the energy exchange between the subharmonic and fundamental modes under conditions where the classical solution disallows any energy exchange between them. This energy exchange is strictly quantum in nature, i.e., it has no classical analog, and exhibits fractional revivals as well as large quantum fluctuations. We demonstrate how the quantum regime of nonlinear optical interactions can be studied in ion traps.

A robust global control strategy, implemented as a spatial filter with delayed feedback, is shown to stabilize and steer the weakly turbulent output of a spatially extended system. The latter is described by a generalized complex Swift-Hohenberg equation [J. Lega, J. V. Moloney, and A. C. Newell, Phys. Rev. Lett. 73, 2978 (1994); Physica D 83, 478 (1995)], which is used as a generic model for pattern formation in the transverse section of semiconductor lasers. Our technique is particularly adapted to optical systems and should provide convenient experimental control of filamentation in wide-aperture lasers.

Decay of an excited molecule (atom) has been considered in an absorbing dielectric. The decay rate has been derived calculating the total rate of excitation transfer to the surrounding species. The contribution due to the far-zone energy transfer yields the rate of photon emission in the absorbing medium. The analysis is based on a microscopic QED theory of energy transfer in condensed phases. As a result, effects due to discreteness of the medium (such as the local field effects) are reflected intrinsically in the decay rates. The microscopic approach supports the previous introduction of the local field factors on a phenomenological basis.

We describe a method for generating a wide spectrum and at the same time improving propagation through a model inhomogeneous gaseous medium. The method is based on using a small two-photon detuning from a Raman resonance to adiabatically establish an appropriate molecular superposition state. This state, in turn, generates a broad spectrum of sidebands whose refractive index, Rayleigh scatter, and accumulated phase delay are much less than those of a single spectral component, if propagating alone.

We show that inseparability of quantum states can be partially broadcasted (copied or cloned) with the help of local operations, i.e., distant parties sharing an entangled pair of spin-1/2 states can generate two pairs of partially nonlocally entangled states using only local operations. This procedure can be viewed as an inversion of quantum purification procedures.

An approach to the problem of violation of causality in classical electrodynamics is proposed. This approach is based on the construction of exact analytic solutions without preacceleration to the Lorentz-Dirac equation in an electrostatic field that vanishes identically outside a certain region. Exact solutions are given for the potential well and the linear potential wall, cases for which Plass [Rev. Mod. Phys. 33, 37 (1961)] already found the corresponding preaccelerative solutions. In addition, an exact solution which differs from the one found by Plass is given for a thin infinite charged plate. Finally, an exact solution is constructed for a special electrostatic field. All these nonpreaccelerative solutions have a jump in the acceleration at points where the electrostatic field has a jump; this implies that they cannot be obtained as solutions to the usual integro-differential equation associated to the Lorentz-Dirac equation.

In this paper, the q Euclidean space and the q deformed harmonic oscillators in this space are described by an algebraic system. In this system we can define the raising (creation) and the lowering (annihilation) operators. These operators form a quantum hyperplane and the corresponding covariant q partial derivatives. From the viewpoint of this quantum hyperplane, the operator q Schrödinger equation and the explanation of its solutions are discussed. In addition, some related q implicate-order structures are presented.

We study the accuracy of several alternative semiclassical methods by computing analytically the energy levels for many large classes of exactly solvable shape-invariant potentials. For these potentials, the ground-state energies computed via the WKB method typically deviate from the exact results by about 10%, a recently suggested modification, using nonintegral Maslov indices, is substantially better, and the supersymmetric WKB quantization method gives exact answers for all energy levels.

The recoil correction of order (Zα${)}^6$(m/M)m to the hydrogen energy levels is recalculated and a discrepancy existing in the literature on this correction for the 1S energy level, is resolved. An analytic expression for the correction to the S levels with arbitrary principal quantum number is obtained.

We consider an analytic solution of the time-dependent Schrödinger equation with the initial condition ψ(x,0)=exp(ikx) along -∞0 of the wave function in a double-barrier resonant structure at resonance. For typical parameters of the structure we find that the single-resonance approximation is valid from a few tenths of the corresponding lifetime onward. Very short times require the contribution of many far away resonances. The buildup time along the internal region takes a few lifetimes. At birth the transmitted wave front is blurred; however, for long times it becomes well defined and moves with classical velocity yielding a delay time τ≈2ℏ/Γ as in the stationary-phase treatment.

We derive entropic Bell inequalities from considering entropy Venn diagrams. These entropic inequalities, akin to the Braunstein-Caves inequalities, are violated for a quantum-mechanical Einstein-Podolsky-Rosen pair, which implies that the conditional entropies of Bell variables must be negative in this case. This suggests that the satisfaction of entropic Bell inequalities is equivalent to the non-negativity of conditional entropies as a necessary condition for separability.