Source-correlation effects are analyzed in the time domain. The autocorrelation function is modified significantly in the presence of source correlations. The modifications of the autocorrelation function are found to be consistent with the Wiener-Khintchine theorem. These predictions are confirmed by experimental studies on laser-light scattering from a rotating ground glass.

We have examined the population oscillation amplitudes, associated attractors, and the order-1 Renyi entropy of Bloch-vector trajectories for a two-level atom interacting with an electromagnetic field, whose phase varies in a two-frequency quasiperiodic manner. Distinct differences in these quantities are observed as the strength of the exciting field varies from weak (nonadiabatic dynamics) to strong (adiabatic dynamics). We find, though, an underlying homology. In all cases the response is two-frequency quasiperiodic with a resulting two-dimensional attractor for the quantum system. Additionally, correlated with observed Rabi resonances, there are abrupt increases in the entropy of the system. A key finding is that Rabi resonances are more than simple increases in the amplitude of a quantum system’s population oscillations; the atomic dynamics abruptly becomes more disordered at these resonances.

We show that correlated photon-number states predicted to violate a Bell’s inequality of the Clauser-Horne-Shimony-Holt type might be generated from parametric amplification. The test is potentially one of macroscopic quantum mechanics in that violations are predicted for situations where a large number of photons are detected in a single detector at one time. The traditional amplifier and detectors allow violation only for regimes where the probability of generation of a macroscopic state is very small. We suggest that this probability may be dramatically improved with the use of squeezing and photon-number-state-preparation techniques.

The problem of electromagnetic-field quantization in time-dependent nonuniform linear nondispersive media is investigated. The explicit formulas for the number of photons generated from the initial vacuum state due to the change in time of dielectric permeability of the medium are obtained in the case when the spatial and temporal dependences are factorized. The concrete time dependences include adiabatic and sudden changes of permeability, the parametric resonance at twice the eigenfrequency of the mode, Epstein’s symmetric and transition profiles, ‘‘temporal Fabry-Pérot resonator,’’ and some others. The upper and lower bounds for the squeezing and correlation coefficients of the field in the final state are given in terms of the reflection coefficient from an equivilent potential barrier or the number of created quanta. The problem of impulse propagation in a spatially uniform but time-dependent dielectric medium is discussed.

The inclusion of spectral cross-relaxation terms, which stem from strong velocity-changing collisions, in the low-dimensional equations, which describe the dynamics of a single-mode, inhomogeneously broadened, unidirectional ring laser, is shown to bring noticeable modifications to the low-excitation self-pulsing phenomena which occur in bad-cavity-configured high-gain lasers. The added cross-relaxation terms are shown to reduce both the first and the second laser threshold. These terms are also shown to modify the pulsation wave forms, and to greatly affect the hierarchy of the dynamical behavior.

The hysteresis curve of the bistable cyclotron motion of a single electron in a magnetic field driven by external microwave radiation is obtained by only varying the phase of a phase-sensitive back-action-evading experimental setup. Thus the steady-state solution of the cyclotron motion includes two branches which could be switched by only changing the phase of the device. This effect is of particular interest as an example of the influence of the noise properties of the measurement apparatus on a microscopic system subjected to measurement.

The interaction of an atomic beam with four traveling-wave laser beams leads to optically induced Ramsey fringes in the atomic beam. This experimental setup has been used as an optical frequency standard as well as a matter-wave interferometer. We calculate for two-level atoms the shift of the fringes due to the influence of fairly general external forces in lowest order of a perturbation approach. A comparison with the phase shift found in a corresponding WKB treatment of the interaction geometry is made. The consequences of beam reversal and cooling of the atomic beam are studied. As an application, we treat the linear acceleration and rotation of the interferometer and discuss the influence of space-time curvature.

The spontaneous-emission coupling factor β for planar microcavities without lateral confinement is measured and calculated for gain media with finite spontaneous-emission linewidth. It is shown that in order to maximize β, the spontaneous-emission linewidth of the gain medium must be smaller or equal to the cold-cavity linewidth. It is also shown that the planar-cavity geometry will give rise to spatial modes, and in order to maximize β one should pump only an area corresponding to one spatial mode. If the pumped area is larger than the lateral extent of a cavity mode, then the mode will grow laterally when pumped above threshold.

We analyze a three-dimensional model of a Klein-Gordon particle in a short-range separable potential and interacting with an intense plane-wave electromagnetic field. In the specific case of the circular polarization of the radiation, we find an exact solution of the Klein-Gordon equation of the system and derive analytic expressions for obtaining the total and partial rates of particle ejection by N-photon absorption, the energy spectrum of the ejected particle, as well as the amplitudes for stimulated bremsstrahlung and its inverse.

We investigate a free monochromatic electromagnetic field which is the superposition of a squeezed thermal radiation and a coherent one. The main tool in our analysis is the characteristic function that has a Gaussian form. We establish an analytic formula for an arbitrary correlation function, as well as its strong-squeezing limit. Besides the usual quasiprobability densities, the coherent-state, number-state, coordinate, and momentum representations of the density operator are derived. We point out the nonclassical oscillations of the photon-number distribution and find its generating function. Collaterally, displaced thermal states and squeezed thermal states are revisited as nontrivial particular cases. We examine finally the squeezing properties of the field using the distribution functions of the quadratures.

We consider a single-mode radiation field initially in a displaced squeezed thermal state. The weak interaction of such a field with a heat bath of arbitrary temperature is shown to preserve the Gaussian form of the characteristic function. Accordingly, the study of the time development of the density operator reduces to our previous description [P. Marian and T. A. Marian, preceding paper, Phys. Rev. A 47, 4474 (1993)] of the initial quantum state. As examples, photon statistics and squeezing properties of the damped field are analyzed. Based on the close relation between field dissipation and photon detection, we derive simple analytic formulas for the counting distribution and its factorial moments. Nonclassical features of a displaced squeezed thermal state, such as oscillations of the photon-number distribution, survive in the counting process, provided that the quantum efficiency of the detector is high enough.

Calculations of the photoionization cross section of the excited 5d state of atomic Cs are performed and found to be in excellent agreement with a recent absolute experiment [M. A. Bouchiat, J. Guena, Ph. Jacquier, and M. Lintz, Chem. Phys. Lett. 199, 85 (1992); M. A. Bouchiat, C. Bouchiat, J. Guena, Ph. Jacquier, and M. Lintz, Z. Phys. D (to be published)].

A nonlocal theory of accelerated observers is developed on the basis of the hypothesis that an electromagnetic wave can never stand completely still with respect to an observer. In the eikonal approximation, the nonlocal theory reduces to the standard extension of Lorentz invariance to accelerated observers. The validity of the nonlocal theory would exclude the possibility of existence of any basic scalar field in nature. The observational consequences of this theory are briefly discussed.

An analytical expression involving three parameters was proposed for atomic momentum-density distributions of K and L shells. This expression was based on the superposition of hydrogenic closed-shell momentum densities. Parameters in the expression were determined by requiring four of its moments to be equal to the corresponding Hartree-Fock results. An analytical function for the Compton profiles was then derived using the impulse approximation. Excellent agreement was found between the present results and detailed theoretical computations.

We present a systematic method for improving any variational wave function. This approach is based on using the variational parameters in a trial wave function to form a family of independent functions that are used to construct a basis for the variational method. We demonstrate the effectiveness of this approach by obtaining fast convergence for the lowest two even-parity energies for Mathieu’s equation and the quartic anharmonic oscillator.

The widely used Roothaan-Hartree-Fock wave functions of Clementi and Roetti [At. Data Nucl. Data Tables 14, 177 (1974)] for the atoms from He through Xe are improved by reoptimization of the exponents of the Slater-type basis functions. The largest improvement in the energy is 0.053 hartree for Cd.

We present results on the complete dispersion interaction between two neutral multilevel atoms in the same excited state. The calculations indicate that the dispersion interaction can produce a repulsive barrier of the order of ≃7 μeV for intermediate separations and that long-range oscillations exist in the Casimir-Polder regime. The results may be of importance in laser-cooled atomic diffusion phenomena where translational energies well below this barrier height are achievable.

The simultaneous measurement of the spatial coordinates and times of p¯s annihilating at rest in a ${\mathrm{H}}_2$ target at very low density ρ (ρ/${\mathrm{\rho }}_0$<${10}^{\mathrm{-}2}$, ${\mathrm{\rho }}_0$ being the STP density) gives the possibility of evaluating the behavior of the p¯ stopping power in ${\mathrm{H}}_2$ at low energies (below 120 keV). It is different from that of protons (the Barkas effect). Moreover, it is shown that a rise at low-energy values (≲1 keV) is needed to agree with experimental data.

The Fock representation of the inverse of harmonic-oscillator creation and annihilation operators [see, e.g., C. L. Mehta, Anil K. Roy, and G. M. Saxena, Phys. Rev. A 46, 1565 (1992)] are naturally derived via a coherent-state approach. The completeness relation of Fock space is reexpressed by the inverse operators. Applications of the inverse operators in studying the phase operators and in normally ordering some operators are given.

A theoretical guide to fabricating materials which could support bistable bright optical solitons in the sense of Kaplan’s definition is presented. The approach is to build up the requisite nonlinearity by combining different media which are known to display saturable Kerr behavior. Conditions on the Kerr coefficients and saturation intensities for bistability to occur are derived.