Highly-efficient state-selective sub-microsecond photoionization detection of single atoms

We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 {\mu}s with an overall detection efficiency {\eta} exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing channel electron multipliers. The scheme enables the calibration of absolute detection efficiencies and might be a key ingredient for future quantum information applications or precision spectroscopy of ultracold atoms.Comment: 4 pages, 4 figure

Short-time scaling behavior of growing interfaces

The short-time evolution of a growing interface is studied within the framework of the dynamic renormalization group approach for the Kadar-Parisi-Zhang (KPZ) equation and for an idealized continuum model of molecular beam epitaxy (MBE). The scaling behavior of response and correlation functions is reminiscent of the ``initial slip'' behavior found in purely dissipative critical relaxation (model A) and critical relaxation with conserved order parameter (model B), respectively. Unlike model A the initial slip exponent for the KPZ equation can be expressed by the dynamical exponent z. In 1+1 dimensions, for which z is known exactly, the analytical theory for the KPZ equation is confirmed by a Monte-Carlo simulation of a simple ballistic deposition model. In 2+1 dimensions z is estimated from the short-time evolution of the correlation function.Comment: 27 pages LaTeX with epsf style, 4 figures in eps format, submitted to Phys. Rev.

Statistical Self-Similarity of One-Dimensional Growth Processes

For one-dimensional growth processes we consider the distribution of the height above a given point of the substrate and study its scale invariance in the limit of large times. We argue that for self-similar growth from a single seed the universal distribution is the Tracy-Widom distribution from the theory of random matrices and that for growth from a flat substrate it is some other, only numerically determined distribution. In particular, for the polynuclear growth model in the droplet geometry the height maps onto the longest increasing subsequence of a random permutation, from which the height distribution is identified as the Tracy-Widom distribution.Comment: 11 pages, iopart, epsf, 2 postscript figures, submitted to Physica A, in an Addendum the distribution for the flat case is identified analyticall

Addressing Sustainability Risks of Bioenergy—Policy Strategies and Corporate Initiatives Energy and Power Engineering

This paper focuses on the sustainable use of solid and gaseous biomass for electricity, heating and cooling. It provides updated findings of policy analyses and corporate strategy analyses performed in the frame of BIOENERGY PROMOTION, one of the flagship projects under the EU Strategy for the Baltic Sea Region. In particular, the paper highlights policies and measures which have been adopted by the EU and EU Member States to address environmental and social sustainability risks of bioenergy. Taking into account the conclusions of BIOENERGY PROMOTION, the paper identifies promising policy developments, but also shortcomings. On the Member State level, the paper refers to the examples of Germany and Poland. It illustrates how problematic policy priorities and policy malfunctioning in two sub-sectors (biogas from energy crops in Germany, biomass co-firing in Poland) led to undesirable environmental and social developments and how policies have been re-adjusted to mitigate sustainability risks. The paper also portrays a number of voluntary corporate sustainability initiatives which emerged due to the lack of a binding European sustainability framework for solid and gaseous biomass. The authors conclude that without a binding sustainability framework at EU level there is a risk of having a patchwork of potentially diverging sustainability regimes and initiatives across Europe causing market intransparency and insecurity for investors

Analysis of the Tuning Sensitivity of Silicon-on-Insulator Optical Ring Resonators

High-quality-factor optical ring resonators have recently been fabricated in thin silicon-on-insulator (SOI). Practical applications of such devices will require careful tuning of the precise location of the resonance peaks. In particular, one often wants to maximize the resonance shift due to the presence of an active component and minimize the resonance shift due to temperature changes. This paper presents a semianalytic formalism that allows the prediction of such resonance shifts from the waveguide geometry. This paper also presents the results of experiments that show the tuning behavior of several ring resonators and find that the proposed semianalytic formalism agrees with the observed behavior

Towards a loophole-free test of Bell's inequality with entangled pairs of neutral atoms

Experimental tests of Bell's inequality allow to distinguish quantum mechanics from local hidden variable theories. Such tests are performed by measuring correlations of two entangled particles (e.g. polarization of photons or spins of atoms). In order to constitute conclusive evidence, two conditions have to be satisfied. First, strict separation of the measurement events in the sense of special relativity is required ("locality loophole"). Second, almost all entangled pairs have to be detected (for particles in a maximally entangled state the required detector efficiency is 82.8%), which is hard to achieve experimentally ("detection loophole"). By using the recently demonstrated entanglement between single trapped atoms and single photons it becomes possible to entangle two atoms at a large distance via entanglement swapping. Combining the high detection efficiency achieved with atoms with the space-like separation of the atomic state detection events, both loopholes can be closed within the same experiment. In this paper we present estimations based on current experimental achievements which show that such an experiment is feasible in future.Comment: 6 pages, 3 figures, to be published in Advanced Science Letter

Physical therapy in wound care a cost-effectiveness analysis

© 2015 Wolters Kluwer Health, Inc. All rights reserved. Management of chronic wounds remains unsatisfactory in terms of treatment cost and time required for complete wound closure (CWC). This study aimed to calculate the healing rates, estimated cost, and time required for CWC in wounds; compare estimated wound care costs between healing and nonhealing wounds; and compare cost effectiveness between venous leg ulcer (VLU) and non-VLU. This was a retrospective cohort study performed at a physical therapy (PT) wound care clinic. Deidentified patient data in the electronicmedical database from September 10, 2012 to January 23, 2015 were extracted. Among 159 included patients with wounds, 119 (74.84%) patients were healed with CWC. The included patients were treated for 109.70±95.70 days, 29.71±25.66 visits, and at the costs per treatment episode of $1629.65±1378.82 per reimbursement rate and$2711.42±2356.81 per breakeven rate. For patients with CWC (healing group), the treatment duration was 98.01±76.12 days with the time for CWC as 72.45±64.21 days; the cost per treatment episode was $1327.24±1143.53 for reimbursement rate and$2492.58±2106.88 for breakeven cost. For patients with nonhealing wounds, treatment duration was found to be longer with costs significantly higher (

Disorder effects in cellular automata for two-lane traffic

For single-lane traffic models it is well known that particle disorder leads to platoon formation at low densities. Here we discuss the effect of slow cars in two-lane systems. Surprisingly, even a small number of slow cars can initiate the formation of platoons at low densities. The robustness of this phenomenon is investigated for different variants of the lane-changing rules as well as for different variants on the single-lane dynamics. It is shown that anticipation of drivers reduces the influence of slow cars drastically.Comment: RevTeX, 22 eps-figures included, 10 page