We study excess noise in a quantum conductor in the presence of constant voltage and alternating external field. Becasue of a two-particle interference effect caused by Fermi correlations the noise is sensitive to the phase of the time-dependent transmission amplitude. We compute spectral density and show that at T=0 the noise has singular dependence on the dc voltage V and the ac frequency Ω with cusplike singularities at integer eV/ħΩ. For a metallic loop with an alternating flux the phase sensitivity leads to an oscillating dependence of the strength of the cusps on the flux amplitude.

The interaction between a tunneling atom in a double potential well and the conduction electrons of different angular momenta results in an anisotropic two-channel orbital Kondo problem, but the Kondo temperature ${\mathit{T}}_{\mathit{K}}$ found earlier has always been somewhat small. That difficulty can be resolved by including some of the excited states of the atom in the well. The ${\mathit{T}}_{\mathit{K}}$ calculated is around 1–10 K in agreement with experiments. The same result can be obtained even if the direct electron assisted tunneling is ignored.

The time evolution of a wave packet within a disordered quantum dot is investigated. It is shown that although the disorder-averaged electron density is nearly homogeneous at times of the order of the diffusive time across the dot, at larger times there is a remarkable evolution towards a state with incrasing correlation with the original state i.e., an echo appears). At long times compared to the inverse mean level spacing the density distirubiton becomes time independent and preserves a memory of the original state. These effects are shown to reveal themselves in the relaxation of current through a quantum dot weakly coupled to reservoirs.

Experimental evidence of a Bose-glass transition in the vortex state of ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_7$ single crystals with columnar defects along the c axis is manifested by the universal critical exponents ${\nu }_{\mathrm{\perp }}$, ${\nu }_{\mathrm{\parallel }}$ (≡ζ${\nu }_{\mathrm{\perp }}$), and z’ derived from the (d’+1)-dimension critical scaling of the frequency-dependent ac resistivity from ${10}^2$ to 2.5×${10}^6$ Hz. The Bose-glass transition temperature (${\mathit{T}}_{\mathrm{BG}}$) is found to decrease with the increasing angle (θ) between the applied magnetic field and the c axis. The finding that ζ=${\nu }_{\mathrm{\parallel }}$/${\nu }_{\mathrm{\perp }}$=1.1±0.1<d’=2 suggests an incompressible Bose glass at temperatures below ${\mathit{T}}_{\mathrm{BG}}$.

We present a microscopic theory for the dc Josephson effect in model mesoscopic constrictions. Our method is based on a non- equilibrium Green function formalism which allows for a self-consistent determination of the order parameter profile along the constriction. The various regimes defined by the different length scales (Fermi wavelength ${\lambda }_{\mathit{F}}$, coherence length ${\xi }_0$, and constriction length ${\mathit{L}}_{\mathit{C}}$) can be analyzed, including the case where all these lengths are comparable. For ${\lambda }_{\mathit{F}}$<̃(${\mathit{L}}_{\mathit{C}}$,${\xi }_0$) phase oscillations with spatial period ${\lambda }_{\mathit{F}}$/2 can be observed. For ${\mathit{L}}_{\mathit{C}}$>${\xi }_0$ solutions with a phase-slip center inside the constriction can be found, in agreement with previous phenomenological theories.

Quasiparticle tunnel junctions where at least one of the electrodes is superconducting are predicted to possess positive thermoelectric power.

A family of ground states at frustrations f=1/2-(1/2)${\mathit{N}}^{\mathrm{-}1}$, with N an integer ≥2, has been observed in the superfluid response of a triangular Josephson junction array as a function of the magnetic flux (∝f) threading a unit cell. These states can be constructed by introducing one- or two-dimensional superlattices of domain walls on the background of the checkerboard ground state at f=1/2, the 1D superlattice (striped phase) being energetically more favorable for N>3. A structural change of the ground state from the striped phase to a 2D superlattice of vacancies is predicted at ${\mathit{f}}_{\mathit{c}}$≊0.468.

The angular dependence of the flux flow resistivity ρ(Θ,T,H) in ${\mathrm{Tl}}_2$${\mathrm{Ba}}_2$${\mathrm{CaCu}}_2$${\mathrm{O}}_8$ is measured as the external field is brought into alignment with heavy-ion-irradiation-induced columnar defects. A flux lock-in state, manifested as a minimum in the ρ(Θ,T,H) data, evolves as the system is cooled deeper into the mixed state. This observation provides compelling evidence for non-zero line tension of vortices in this highly anisotropic superconductor. The temperature dependence of the flux flow resistivity at perfect alignment is consistent with Bose glass theory of vortex localization at columnar defects.

The Fredholm determinant associated with the Bogoliubov Hamiltonians H and ${\mathit{H}}_0$ (eigenvalues ${\mathit{E}}_{\mathit{j}}$ and ${\mathit{E}}_{\mathit{j}0}$) is D(ζ)==${\mathit{tprod}}_{\mathit{j}}$ (ζ-${\mathit{E}}_{\mathit{j}}$)/(ζ-${\mathit{E}}_{\mathit{j}0}$), where ζ is a complex number. D(ζ) holds all possible information on the one-particle excitation spectra of the BCS superfluids described by H and ${\mathit{H}}_0$. For three-dimensional systems with order parameters and potentials varying along the x axis, we show that D(ζ) may be calculated from a finite matrix that transports eigenfunctions along this axis. For piecewise-constant order parameters and potentials, D(ζ) can be found in closed form.

Mounds of gold atoms of horizontal size less than 200 Å and height <20 Å, and pits of width <50 Å and depth <10 Å can be produced on a gold surface with nearly equal probabilities by applying voltage pulses to a gold tip in the scanning tunneling microscope. We study the effects of the polarity and the height of the applied voltage pulses, and those of atmospheric environments. Our data show that field evaporation can occur both in positive and negative fields, but in ultrahigh vacuum, a tip can sustain itself only if it is in negative polarity.

Exposure of Cs surfaces to ${\mathrm{O}}_2$ causes the emission of exoelectrons. With a Cs monolayer on Ru(0001) the maximum yield is observed with an already partly oxidized surface on which a metastable ${\mathrm{O}}_2^{\mathrm{-}}$ species could be identified. Thermally activated transformation (with an activation energy of 0.8 eV) of this phase leads to dissociation accompanied by exoelectron emission via Auger deexcitation.

We investigate the phase diagram of mixtures of charge stabilized polystyrene spheres of two different sizes in the hard-sphere limit. We observe bulk phase separation into two disordered phases and find a new ordered phase located on the cell walls. The ordered phase occurs at volume fractions as low as 0.2, much less than the value of 0.49 for hard-sphere freezing in monodisperse suspensions, and is qualitatively explained with simple geometric arguments.

The renormalizability of the self-avoiding manifold Edwards model is established. We use a new short distance multilocal operator product expansion, which extends methods of local field theories to a large class of models with nonlocal singular interactions. This validates the direct renormalization method introduced before, as well as scaling laws. A new general hyperscaling relation is derived. Manifolds at the FTHETA point and long-range Coulomb interactions are briefly discussed.

We analyze the low energy behavior of interacting fermions in continuous dimensions d between one and two. It is shown that Fermi liquid fixed points are stable with respect to residual scattering of quasiparticles by regular interactions in any dimension above one, while the structure of corrections to quasiparticle behavior changes drastically below two dimensions. The crossover from Luttinger liquid behavior in 1D to Fermi liquid behavior in higher dimensions is described by a tomographic Luttinger model with effective interactions approaching zero with a power d-1 of the distance from the Fermi surface.

The nonlinear dynamics of cosmological perturbations of an irrotational collisionless fluid is analyzed within general relativity. Relativistic and Newtonian solutions are compared, stressing the different role of boundary conditions in the two theories. Cosmological implications of relativistic effects, already present at second order in perturbation theory, are studied and the dynamical role of the magnetic part of the Weyl tensor is elucidated.

We report the measurement of masses and widths of the following L=1 charm mesons by the E687 Collaboration at Fermilab: a ${\mathit{D}}_2^{\mathrm{*}0}$ state of mass (width) 2453±3±2 (25±10±5) MeV/${\mathit{c}}^2$ decaying to ${\mathit{D}}^{+}$${\mathrm{\pi }}^{\mathrm{-}}$, a ${\mathit{D}}_2^{\mathrm{*}+}$ state of mass (width) 2453±3±2 (23±9±5) MeV/${\mathit{c}}^2$ decaying to ${\mathit{D}}^0$${\mathrm{\pi }}^{+}$, a ${\mathit{D}}_1^0$ state of mass (width) 2422±2±2 (15±8±4) MeV/${\mathit{c}}^2$ decaying to ${\mathit{D}}^{\mathrm{*}+}$${\mathrm{\pi }}^{\mathrm{-}}$, and a ${\mathit{D}}_{\mathit{s}1}^{+}$ state of mass 2535.0±0.6±1.0 MeV/${\mathit{c}}^2$ and width <3.2 MeV/${\mathit{c}}^2$ at 90% confidence level, decaying to ${\mathit{D}}^{\mathrm{*}+}$${\mathit{K}}_{\mathit{s}}^0$ and ${\mathit{D}}^{\mathrm{*}0}$${\mathit{K}}^{+}$.

We report on new precision measurements of the 1S ground state Lamb shift in hydrogen and deuterium, based on a direct frequency comparison of the 1S-2S and 2S-4S two-photon resonances. By observing the 2S-4S transition via blue Balmer-β fluorescence we are now surpassing the accuracy of the 2S Lamb shift. Our results of 8172.86(6) MHz for hydrogen and 8184.00(8) MHz for deuterium are not in perfect agreement with the theoretical predictions of 8173.12(6) and 8184.13(6) MHz, respectively. We also derive values for the Rydberg constant and the electron-proton mass ratio.

We investigate electron capture from initially oriented circular Rydberg atoms by proton impact at collision speeds comparable to the electron orbital speed. The Thomas double scattering mechanism is observed even at these low relative speeds. Furthermore, we find evidence for the dominance of a quasi Thomas capture mechanism in the form of not a single peak, but a double-peaked structure in the differential cross section when the plane of the circular orbit is nearly perpendicular to the incident direction of the projectile.

The inertial-range scaling laws of fully developed turbulence are described in terms of scalings of a sequence of moment ratios of the energy dissipation field ${\mathrm{\epsilon }}_{\mathit{l}}$ coarse-grained at inertial-range scale l. These moment ratios ${\mathrm{\epsilon }}_{\mathit{l}}^{\left(\mathit{p}\right)}$=〈${\mathrm{\epsilon }}_{\mathit{l}}^{\mathit{p}+1\mathrm{}}$〉/〈${\mathrm{\epsilon }}_{\mathit{l}}^{\mathit{p}}$〉(p=0, 1, 2,...,) form a hierarchy of structures. The most singular structures ${\mathrm{\epsilon }}_{\mathit{l}}^{\left(\mathrm{\infty }\right)}$ are assumed to be filaments, and it is argued that ${\mathrm{\epsilon }}_{\mathit{l}}^{\left(\mathrm{\infty }\right)}$∼${\mathit{l}}^{\mathrm{-}2/3}$. Furthermore, a universal relation between scalings of successive structures is postulated, which leads to a prediction of the entire set of the scaling exponents: 〈${\mathrm{\epsilon }}_{\mathit{l}}^{\mathit{p}}$〉∼${\mathit{l}}_{\mathit{p}}^{\mathrm{\tau }}$, ${\mathrm{\tau }}_{\mathit{p}}$=-2/3p+2[1-( 2) / 3 ${)}^{\mathit{p}}$] and 〈δ${\mathit{v}}_{\mathit{l}}^{\mathit{p}}$〉∼${\mathit{l}}_{\mathit{p}}^{\mathrm{\zeta }}$, ${\mathrm{\zeta }}_{\mathit{p}}$=p/9+2[1-(2/3${)}^{\mathit{p}/3\mathrm{}}$].

Three complex ordinary differential equations, modeling interactions in wall-bounded turbulent flow, are developed and studied. It is believed that the roll-wave interactions which are included are of fundamental importance to turbulence production. Integration of these triad equations is shown to be consistent with direct flow simulations and the Ruelle-Takens route to chaos.