Waiting times of entangled electrons in normal-superconducting junctions

We consider a normal-superconducting junction in order to investigate the effect of new physical ingredients on waiting times. First, we study the interplay between Andreev and specular scattering at the interface on the distribution of waiting times of electrons or holes separately. In that case the distribution is not altered dramatically compared to the case of a single quantum channel with a quantum point contact since the interface acts as an Andreev mirror for holes. We then consider a fully entangled state originating from spliting of Cooper pairs at the interface and demonstrate a significant enhancement of the probability to detect two consecutive electrons in a short time interval. Finally, we discuss the electronic waiting time distribution in the more realistic situation of partial entanglement

Photo-assisted shot noise in Coulomb interacting systems

We consider the fluctuations of the electrical current (shot noise) in the presence of a voltage time-modulation. For a non-interacting metal, it is known that the derivative of the photo-assisted noise has a staircase behavior. In the presence of Coulomb interactions, we show that the photo-assisted noise presents a more complex profile, in particular for the two following systems: 1) a two-dimensional electron gas in the fractional quantum Hall regime for which we have obtained evenly spaced singularities in the noise derivative, with a spacing related to the filling factor and, 2) a carbon nanotube for which a smoothed staircase in the noise derivative is obtained.Comment: Proceedings of the 6th Rencontres du Vietnam, Hanoi (2006

An electronic Mach-Zehnder interferometer in the Fractional Quantum Hall effect

We compute the interference pattern of a Mach-Zehnder interferometer operating in the fractional quantum Hall effect. Our theoretical proposal is inspired by a remarkable experiment on edge states in the Integer Quantum Hall effect (IQHE). The Luttinger liquid model is solved via two independent methods: refermionization at nu=1/2 and the Bethe Ansatz solution available for Laughlin fractions. The current differs strongly from that of single electrons in the strong backscattering regime. The Fano factor is periodic in the flux, and it exhibits a sharp transition from sub-Poissonian (charge e/2) to Poissonian (charge e) in the neighborhood of destructive interferences

Complexity of vaginal microflora as analyzed by PCR denaturing gradient gel electrophoresis in a patient with recurrent bacterial vaginosis.

OBJECTIVE: Gardnerella vaginalis has long been the most common pathogen associated with bacterial vaginosis (BV). We aimed to test our hypothesis that symptoms and signs of BV do not necessarily indicate colonization by this organism, and often will not respond to standard metronidazole or clindamycin treatment. METHODS: Using a relatively new molecular tool, PCR denaturing gradient gel electrophoresis (DGGE), the vaginal microflora of a woman with recalcitrant signs and symptoms of BV was investigated over a 6-week timeframe. RESULTS: The vagina was colonized by pathogenic enterobacteriaceae, staphylococci and Candida albicans. The detection of the yeast by PCR-DGGE is particularly novel and enhances the ability of this tool to examine the true nature of the vaginal microflora. The patient had not responded to antifungal treatment, antibiotic therapy targeted at anaerobic Gram-negative pathogens such as Gardnerella, nor daily oral probiotic intake of Lactobacillus rhamnosus GG. The failure to find the GG strain in the vagina indicated it did not reach the site, and the low counts of lactobacilli demonstrated that therapy with this probiotic did not appear to influence the vaginal flora. CONCLUSIONS: BV is not well understood in terms of its causative organisms, and further studies appear warranted using non-culture, molecular methods. Only when the identities of infecting organisms are confirmed can effective therapy be devized. Such therapy may include the use of probiotic lactobacilli, but only using strains which confer a benefit on the vagina of pre- and postmenopausal women

The evaluation of evaporation by infrared thermography: A critical analysis of the measurements on the Crau test site

Evapotranspiration was calculated for both the dry and irrigated zone by four methods which were compared with the energy balance method serving as a reference. Two methods did not involve the surface temperature. They are ETR(n) = R(n), liable to be valid under wet conditions and ET(eq) = (delta/delta + gamma) R(n) i.e, the first term of Penman's equation, adapted to moderately dry conditions. The methods using surface temperature were the combined energy balance aerodynamic approach and a simplified approach proposed by Jackson et al. Tests show the surface temperature methods give relatively satisfactory results both in the dry and wet zone, with a precision of 10% to 15% compared with the reference method. As was to be expected, ET(eq) gave satisfactory results only in the dry zone and ET(Rn) in the irrigated zone. Thermography increased the precision in the estimate of ET relative to the most suitable classical method by 5% to 8% and is equally suitable for both dry and wet conditions. The Jackson method does not require extensive ground measurements and the evaluation of the surface roughness

Présence de spirochetes dans des lésions cutanées du porcelet

Rossi Paul, Devillard J.-P. Présence de spirochètes dans des lésions cutanées du porcelet (3 figures). In: Bulletin de l'Académie Vétérinaire de France tome 110 n°4, 1957. pp. 155-161

Size segregation and convection

The size segregation of granular materials in a vibrating container is investigated using Molecular Dynamics. We find that the rising of larger particles is accompanied by the existence of convection cells even in the case of the lowest possible frequencies. The convection can, however, also be triggered by the larger particle itself. The possibility of rising through this mechanism strongly depends on the depth of the larger particle.Comment: 7 pages, 4 figure

Numerical study of a non-equilibrium interface model

We have carried out extensive computer simulations of one-dimensional models related to the low noise (solid-on-solid) non-equilibrium interface of a two dimensional anchored Toom model with unbiased and biased noise. For the unbiased case the computed fluctuations of the interface in this limit provide new numerical evidence for the logarithmic correction to the subnormal L^(1/2) variance which was predicted by the dynamic renormalization group calculations on the modified Edwards-Wilkinson equation. In the biased case the simulations are in close quantitative agreement with the predictions of the Collective Variable Approximation (CVA), which gives the same L^(2/3) behavior of the variance as the KPZ equation.Comment: 15 pages revtex, 4 Postscript Figure

Josephson junction chains with long-range interactions: Phase slip proliferation versus Kosterlitz-Thouless transition

The role of long range badly screened Coulomb interactions in a one-dimensional chain of Josephson junctions is studied. Correlation functions for the phase correlator are obtained as a function of the Josephson coupling energy, the short range part of Coulomb repulsion and its long range component. Though quasi-long range order is no longer possible and the usual Kosterlitz-Thouless transition no longer exists, there are remnants of it. As an application, we calculate the $I-V$ curves for Andreev reflexion when a normal metal is placed in contact with the chain. Formally, there is always an offset voltage $V_0$ below which no current can flow, however, in some regimes $V_0$ can be negligible. Contrary to what happens without long-range interactions, the Andreev current, as a function of applied voltage, increases faster than any power law. Signatures of long range interactions and phase slips appear in the $I-V$ curves. Possible application for quasi one-dimensional thin superconducting wires is outlined.Comment: 22 pages, 6 figures, accepted in Phys. Rev. B (2011