We show that coorbital dynamics at large eccentricity and inclination exhibit hitherto unknown types of stable motion in the gravitational three-body problem. In the solar system, the secular stability is observed in the evolution of specific near-Earth asteroids. In particular, the slow diffusion of such objects through the Earth's coorbital region which leads to temporary capture suggests the existence of undiscovered retrograde moons of the Earth. In the Coulomb problem, the Kozai resonance is a primary candidate for stable low angular momentum states in two-electron atoms.

Thin films of Cs are covered with $\frac{1}{100}$ of a monolayer of Fe or Co. Then the impurities are covered with several atomic layers of Cs. The magnetization of the films is measured by means of the anomalous Hall effect. The magnetization follows a Brillouin function with a magnetic moment of about 8 Bohr magnetons for Co on the surface and in the bulk of the Cs. For the Fe impurities, a magnetic moment of 7 Bohr magnetons is observed. These large moments suggest that the $3d$ impurities polarize the conduction electrons of the Cs similar to the giant moments in Pd.

We introduce a new method of controlling chaos that retains the essential features of occasional proportional feedback, but is much simpler to implement. We demonstrate control on a simple piecewise-linear Rossler circuit operating near 1 kHz and a Colpitts oscillator with a fundamental frequency of 19 MHz. As a result of the simplicity of our technique, control of chaos has been accomplished for the fastest chaotic system reported to date.

We used a spatially broadband optical parametric amplifier for image amplification. In the phase-sensitive configuration of the amplifier, we observed noiseless amplification of input images. For a gain of $\simeq 2.5$, we measured noise-figure values of ( $0.2\pm 0.6$) and ( $0.4\pm 0.5$) dB, respectively, for two amplifiers of different lengths. These experimental values agree with theory (for an ideal noiseless amplifier the noise figure is 0 dB) and are almost 2 dB lower than the quantum limit of an ideal phase-insensitive amplifier.

In open-shield systems, we have derived current conditions that lead to remarkable magnetic-field confinement, which we call “supershielding.” The freedom to vary both primary and shield currents is important in solving the conditions. Solutions leading to very effective shielding are illustrated by the simple system of two parallel flat strips. Generalizations include other geometries, internal shielding, and electric-field confinement. An industrial coil design serves as a reference for practical issues. We discuss mathematical limits, via a “seesaw” approach, to “perfect shielding.”

Quantum jumps between Fock states of a one-electron oscillator reveal the quantum limit of a cyclotron. With a surrounding cavity inhibiting synchrotron radiation 140-fold, the jumps show a 13 s Fock state lifetime and a cyclotron in thermal equilibrium with 1.6 to 4.2 K blackbody photons. These disappear by 80 mK, a temperature 50 times lower than previously achieved with an isolated elementary particle. The cyclotron stays in its ground state until a resonant photon is injected. A quantum cyclotron offers a new route to measuring the electron magnetic moment and the fine structure constant.

We show that results from the theory of random matrices are potentially of great interest to understand the statistical structure of the empirical correlation matrices appearing in the study of multivariate time series. The central result of the present study, which focuses on the case of financial price fluctuations, is the remarkable agreement between the theoretical prediction (based on the assumption that the correlation matrix is random) and empirical data concerning the density of eigenvalues associated to the time series of the different stocks of the S&P 500 (or other major markets). In particular, the present study raises serious doubts on the blind use of empirical correlation matrices for risk management.

We use methods of random matrix theory to analyze the cross-correlation matrix $\mathbf{C}$ of stock price changes of the largest 1000 U.S. companies for the 2-year period 1994–1995. We find that the statistics of most of the eigenvalues in the spectrum of $\mathbf{C}$ agree with the predictions of random matrix theory, but there are deviations for a few of the largest eigenvalues. We find that $\mathbf{C}$ has the universal properties of the Gaussian orthogonal ensemble of random matrices. Furthermore, we analyze the eigenvectors of $\mathbf{C}$ through their inverse participation ratio and find eigenvectors with large ratios at both edges of the eigenvalue spectrum—a situation reminiscent of localization theory results.

Following a prediction by Smolańczuk [Phys. Rev. C 59, 2634 (1999)], we searched for superheavy element formation in the bombardment of ${}^{208}\mathrm{Pb}$ with 449-MeV ${}^{86}\mathrm{Kr}$ ions. We have observed three decay chains, each consisting of an implanted heavy atom and six subsequent $\alpha$ decays, correlated in time and position. In these decay chains, a rapid (ms) sequence of high energy $\alpha$ particles ( $E_{\alpha }\ge 10\mathrm{MeV}$) indicates the decay of a new high- $Z$ element. The observed chains are consistent with the formation of ${}_{}{}^{293}{}_{}{}^{}118$ and its decay by sequential $\alpha$-particle emission to ${}_{}{}^{289}{}_{}{}^{}116$, ${}_{}{}^{285}{}_{}{}^{}114$, ${}_{}{}^{281}{}_{}{}^{}112$, ${}_{}{}^{277}{}_{}{}^{}110$, ${}^{273}\mathrm{Hs}$ ( $Z=108\mathrm{}$) and ${}^{269}\mathrm{Sg}$ ( $Z=106\mathrm{}$). The production cross section is ${2.2}_{-0.8\mathrm{}}^{+2.6\mathrm{}}\mathrm{pb}$.

We address the dynamics of a drop with viscosity $\lambda \eta$ breaking up inside another fluid of viscosity $\eta$. We track the time evolution of the drop near snap-off in the experiments and then compare with a scaling theory developed for $\lambda =1\mathrm{}$. The theory is in excellent agreement with both the experiments and the previous simulations of Lister and Stone. Finally, we also investigate the $\lambda$ dependence of the drop shape and breaking rate, and develop a simple theory for the latter.

We demonstrate that when an optically birefringent nematic liquid crystal is infiltrated into the void regions of an inverse opal, photonic-band-gap (PBG) material, the resulting composite material exhibits a completely tunable PBG. In particular, the three-dimensional PBG can be completely opened or closed by applying an electric field which rotates the axis of the nematic molecules relative to the inverse opal backbone. Tunable light localization effects may be realized by controlling the orientational disorder in the nematic.

Measurements of the distances to type Ia supernovae have produced strong evidence that the expansion of the Universe is accelerating, implying the existence of a nearly uniform component of dark energy with negative pressure. We show that constraints to this mysterious component based upon large-scale structure nicely complement the SN Ia data, and that together they require ${\Omega }_X={\rho }_X/{\rho }_{\mathrm{crit}}\in (0.6,0.7)$ and ${w=p}_X/{\rho }_X<-0.6\mathrm{}$ ( $95\%$ C.L.), for the favored flat Universe. Other cosmological data support this conclusion. The simplest explanation, a cosmological constant, is consistent with this, while some of the other possibilities are not.

Dynamic force spectroscopy was applied to single specific bonds between immunoglobulins of type G and protein A, a staphylococcal receptor for IgG. The resulting spectra of yield forces indicated the crossover from force induced to spontaneous bond dissociation. Moreover, failure of unloaded bonds was observed directly. Extrapolation to vanishing loading rate and direct observation yielded coinciding results.

We consider two different ways to encode quantum information, by parallel or antiparallel pairs of spins. We find that there is more information in the antiparallel ones. This purely quantum mechanical effect is due to entanglement, not of the states but occurring in the course of the measuring process. We also introduce a range of quantum information processing machines, such as spin flip and anticloning.

We have compared the decay rates of $K_L$ and $K_S$ to ${\pi }^{+}{\pi }^{-}$ and ${\pi }^0{\pi }^0$ final states using a subset of the data from the KTeV experiment (E832) at Fermilab. We find that the direct-CP-violation parameter $\mathrm{Re}\left({\epsilon }^{\prime }/\epsilon \right)$ is equal to $[28.0\pm 3.0(\mathrm{stat})\pm 2.8(\mathrm{syst}\left)\right]\times {10}^{-4\mathrm{}}$. This result definitively establishes the existence of CP violation in a decay process.

The ${}^{17}\mathrm{F}(p,\gamma {)}^{18}\mathrm{Ne}$ reaction is important in stellar explosions, but its rate has been uncertain because of an expected $3^{+}$ state in ${}^{18}\mathrm{Ne}$ that has never been conclusively observed. This state would provide a strong $\ell =0\mathrm{}$ resonance and, depending on its excitation energy, could dominate the stellar reaction rate. We have observed this missing $3^{+}$ state by measuring the ${}^1\mathrm{H}{(}^{17}\mathrm{F},p{)}^{17}\mathrm{F}$ excitation function with a radioactive ${}^{17}\mathrm{F}$ beam at the ORNL Holifield Radioactive Ion Beam Facility. We find that the state lies at a center-of-mass energy of $E_r=599.8\mathrm{}\pm 1{.5}_{\mathrm{stat}}\pm {2.0}_{\mathrm{sys}}\mathrm{keV}$ ( $E_x=4523.7\mathrm{}\pm 2.9\mathrm{keV}$) and has a width of $\Gamma =18\mathrm{}\pm 2_{\mathrm{stat}}\pm 1_{\mathrm{sys}}\mathrm{keV}$.

We report the observation of small group velocities of order 90 m/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas ( $\approx 360\mathrm{K}$). Media of this kind yield strong nonlinear interactions between very weak optical fields and very sharp spectral features. The result is in agreement with previous studies on nonlinear spectroscopy of dense coherent media.

The electronic and phase-coherent transport properties of doped carbon nanotube junctions are studied. It is shown that there are regions of negative differential resistance in the $I-V$ characteristic of small radius metallic tubes, which are not seen for semiconducting tubes. Their origin, as discussed, is different from that of traditional Esaki diodes and resonant tunneling structures. Semiconducting tube characteristics, however, show a region of zero current for nonzero voltages which is asymmetric with respect to the applied bias if there is different doping on each side of the junction.

In the high-κ cubic superconductor ${\mathrm{V}}_3\mathrm{Si}$, phase transitions of the flux lattice structure occur as a function of applied field and temperature. With the field parallel to the fourfold [001] axis, the flux lattice transforms from triangular to square symmetry at approximately 1 T. With the field parallel to the twofold [110] axis, the lattice, which is a nearly perfect hexagonal array at the lowest fields, distorts as the field is increased; the rate of increase in this distortion changes abruptly at 1.3 T. As $T_c$ is approached, the system tends towards a more isotropic hexagonal array of the flux lines. These transitions are largely but not completely in agreement with a recent theory of the effects on the flux line arrangements of nonlocal electrodynamics in the London limit.

A new technique for determining electron impact metastable excitation cross sections which exploits angular deflection of the target is presented. The deflected targets, further excited by laser radiation which is resonant between the metastable state and a high- $n$ Rydberg state, are detected using field ionization. The target deflection angle and flight time determines the associated electron scattering angle, whereas the laser probes individual states of the electron excited manifold. New information over a full range of scattering angles from forward to backward scattering is then obtained.