CoCoME with Security

In this technical report we provide the documentation of the functional requirements of a component-based system representing the IT infrastructure supermarket along with the description of confidentiality properties in the form of information flow requirements for the system. From an architectural point of view, we describe for each interface all services on a functional level. We identify a number of possible attackers and assign for each attacker what inputs to the system she may gain knowledge about and which outputs she may be able to observe. The architecture and security properties of the system are modeled using an extension of the Palladio Component Model

Scaling of transmission capacities in coarse-grained renewable electricity networks

Network models of large-scale electricity systems feature only a limited spatial resolution, either due to lack of data or in order to reduce the complexity of the problem with respect to numerical calculations. In such cases, both the network topology, the load and the generation patterns below a given spatial scale are aggregated into representative nodes. This coarse-graining affects power flows and thus the resulting transmission needs of the system. We derive analytical scaling laws for measures of network transmission capacity and cost in coarse-grained renewable electricity networks. For the cost measure only a very weak scaling with the spatial resolution of the system is found. The analytical results are shown to describe the scaling of the transmission infrastructure measures for a simplified, but data-driven and spatially detailed model of the European electricity system with a high share of fluctuating renewable generation.Comment: to be published in EP

Probing the Superfluid to Mott Insulator Transition at the Single Atom Level

Quantum gases in optical lattices offer an opportunity to experimentally realize and explore condensed matter models in a clean, tunable system. We investigate the Bose-Hubbard model on a microscopic level using single atom-single lattice site imaging; our technique enables space- and time-resolved characterization of the number statistics across the superfluid-Mott insulator quantum phase transition. Site-resolved probing of fluctuations provides us with a sensitive local thermometer, allows us to identify microscopic heterostructures of low entropy Mott domains, and enables us to measure local quantum dynamics, revealing surprisingly fast transition timescales. Our results may serve as a benchmark for theoretical studies of quantum dynamics, and may guide the engineering of low entropy phases in a lattice

Non-Interference with What-Declassification in Component-Based Systems

Component-based design is a method for modular design of systems. The structure of component-based systems follows specific rules and single components make assumptions on the environment that they run in. In this paper, we provide a noninterference property for component-based systems that allows for a precise specification of what-declassification of information and takes assumptions on the environment into consideration in order to allow a modular, precise and re-usable information-flow analysis. For precise analysis, components can be analyzed by separately analysing services provided by a component, and from our compositionality theorem non-interference of components follows

A Quantum Gas Microscope for Detecting Single Atoms in a Hubbard-Regime Optical Lattice

Recent years have seen tremendous progress in creating complex atomic many-body quantum systems. One approach is to use macroscopic, effectively thermodynamic ensembles of ultracold atoms to create quantum gases and strongly correlated states of matter, and to analyze the bulk properties of the ensemble. For example, bosonic and fermionic atoms in a Hubbard regime optical lattice 1, 2, 3, 4, 5 allow experimenters to carry out quantum simulations of solid state models 6, thereby addressing fundamental questions of condensed matter physics. The opposite approach is to build up microscopic quantum systems atom by atom – with complete control over all degrees of freedom 7, 8, 9. The atoms or ions act as qubits and allow experimenters to realize quantum gates with the goal of creating highly controllable quantum information systems. Until now, the macroscopic and microscopic strategies have been fairly disconnected. Here, we present a “quantum gas microscope” that bridges the two approaches, realizing a system where atoms of a macroscopic ensemble are detected individually and a complete set of degrees of freedom of each of them is determined through preparation and measurement. By implementing a high-resolution optical imaging system, single atoms are detected with near-unity fidelity on individual sites of a Hubbard regime optical lattice. The lattice itself is generated by projecting a holographic mask through the imaging system. It has an arbitrary geometry, chosen to support both strong tunnel coupling between lattice sites and strong on-site confinement. On one hand, this new approach can be used to directly detect strongly correlated states of matter. In the context of condensed matter simulation, this corresponds to the detection of individual electrons in the simulated crystal with atomic resolution. On the other hand, the quantum gas microscope opens the door for the addressing and readout of large-scale quantum information systems with ultracold atoms.Physic