Non-Fraunhofer interference pattern in inhomogeneous ferromagnetic Josephson junctions

Generic conditions are established for producing a non-Fraunhofer response of the critical supercurrent subject to an external magnetic field in ferromagnetic Josephson junctions. Employing the quasiclassical Keldysh-Usadel method, we demonstrate theoretically that an inhomogeneity in the magnitude of the energy scales in the system, including Thouless energy, exchange field and temperature gradient normal to the transport direction, influences drastically the standard Fraunhofer pattern. The exotic non-Fraunhofer response, similar to that observed in recent experiments, is described in terms of an intricate interplay between multiple "0-π" states and is related to the appearance of proximity vortices.     

Efficient quantification of non-gaussian spin distributions

We study theoretically and experimentally the quantification of non-gaussian distributions via nondestructive measurements. Using the theory of cumulants, their unbiased estimators, and the uncertainties of these estimators, we describe a quantification which is simultaneously efficient, unbiased by measurement noise, and suitable for hypothesis tests, e.g., to detect nonclassical states. The theory is applied to cold 87Rb spin ensembles prepared in non-gaussian states by optical pumping and measured by nondestructive Faraday rotation probing. We find an optimal use of measurement resources under realistic conditions, e.g., in atomic ensemble quantum memories.     

A multiscale material point method for impact simulation

To better simulate multi-phase interactions involving failure evolution, the material point method (MPM) has evolved for almost twenty years. Recently, a particle-based multiscale simulation procedure is being developed, within the framework of the MPM, to describe the detonation process of energetic nano-composites from molecular to continuum level so that a multiscale equation of state could be formulated. In this letter, a multiscale MPM is proposed via both hierarchical and concurrent schemes to simulate the impact response between two microrods with different nanostructures. Preliminary results are presented to illustrate that a transition region is not required between different spatial scales with the proposed approach.     

Novel half space radiation mode method for buried waveguide analysis

A new method is presented for the analysis of buried rectangular waveguides in the presence of a plane semiconductor–air interface. The method uses simple radiation modes for a half space to formulate closed form transcendental equations for the propagation constants in the scalar and polarized cases. Results are thereby obtained very efficiently and are shown to be highly accurate when compared to benchmark results obtained with the Finite Difference method.     

FTIR Emission Spectra, Molecular Constants, and Potential Curve of Ground State GeO

Extensive new high-temperature, high-resolution FTIR emission spectroscopy measurements for the five common isotopomers of GeO are combined with previous diode laser and microwave measurements in combined isotopomer analyses. New Dunham expansion parameters and an accurate analytical potential energy function are determined for the ground X1Sigma+ state. Copyright 1999 Academic Press.     

Quantum Macrostatistical Picture of Nonequilibrium Steady States

We apply our quantum macrostatistical treatment of irreversible processes to prove that, in nonequilibrium steady states, (a) the hydrodynamical observables execute a generalised Onsager–Machlup process and (b) the spatial correlations of these observables are generically of long range. The key assumptions behind these results are a nonequilibrium version of Onsager regression hypothesis, together with certain hypotheses of chaoticity and local equilibrium for hydrodynamical fluctuations.     

The 2002 International Workshop on Optical Waveguide Theory and Numerical Modelling

Optical and Quantum Electronics -     

Off-diagonal long-range order and the Meissner effect

We provide a general, model-independent, derivation of the Meissner effect, on the basis of assumptions of off-diagonal long-range order (ODLRO) and gauge covariance of the second kind. This is an exact result that is independent of the microscopic mechanism responsible for the ordering, and so is applicable both to high- and low-T _c superconductors.     

Use of ion-exclusion chromatography for monitoring fatty acids produced by bacterial anaerobic degradation of tetrachloroethene in ground water

A rapid method for the simultaneous quantification of non-volatile and volatile fatty acids in aqueous sample by ion-exclusion chromatography is described. The sample is directly injected into the column and detected by a chemically suppressed conductivity detector, connected in tandem with an UV detector at 210 nm. The method allows detection of fatty acid as low as 1 ppm with a linear dynamic range up to 1000 ppm. At least 13 fatty acids can be determined within 50 min. This technique has been used to monitor the common fermentation products (lactate, acetate, propionate and butyrate) of the reductive dehalogenation of tetrachloroethene by anaerobic bacteria.