University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Indistinguishable photons from independent semiconductor nanostructures.

Abstract: We demonstrate quantum interference between photons generated by the radiative decay processes of excitons that are bound to isolated fluorine donor impurities in ZnSe/ZnMgSe quantum-well nanostructures. The ability to generate single photons from these devices is confirmed by autocorrelation experiments, and the indistinguishability of photons emitted from two independent nanostructures is confirmed via a Hong-Ou-Mandel dip. These results indicate that donor impurities in appropriately engineered semiconductor structures can portray atomlike homogeneity and coherence properties, potentially enabling scalable technologies for future large-scale optical quantum computers and quantum communication networks.

Rule-Based Specification of Behavioral Consistency Based on the UML Meta-model

Abstract: Object-oriented modeling favors the modeling of object behavior from different viewpoints and at different levels of abstraction. This gives rise to consistency problems between overlapping or semantically related submodels. The absence of a formal semantics for the UML and the numerous ways of employing the language within the development process lead to a number of different consistency notions. Therefore, general meta-level techniques are required for specifying, analyzing, and communicating consistency constraints. In this paper, we discuss the issue of consistency of behavioral models in the UML and present techniques for specifying and analyzing consistency. Using meta-model rules we transform elements of UML models into a semantic domain. Then, consistency constraints can by specified and validated using the language and the tools of the semantic domain. This general methodology is exemplified by the problem of protocol statechart inheritance.

Gaussian Boson sampling

Abstract: We present the protocol for Gaussian Boson Sampling with single-mode squeezed states. We eliminate heralding and show that our proposal with the Hafnian matrix function can retain the higher photon number contributions at the input.

Roadmap on quantum light spectroscopy

Abstract: Conventional spectroscopy uses classical light to detect matter properties through the variation of its response with frequencies or time delays. Quantum light opens up new avenues for spectroscopy by utilizing parameters of the quantum state of light as novel control knobs and through the variation of photon statistics by coupling to matter. This Roadmap article focuses on using quantum light as a powerful sensing and spectroscopic tool to reveal novel information about complex molecules that is not accessible by classical light. It aims at bridging the quantum optics and spectroscopy communities which normally have opposite goals: manipulating complex light states with simple matter e.g. qubits versus studying complex molecules with simple classical light, respectively. Articles cover advances in the generation and manipulation of state-of-the-art quantum light sources along with applications to sensing, spectroscopy, imaging and interferometry.

How far do chemotaxis-driven forces influence regularity in the Navier-Stokes system?

Abstract: A three-dimensional chemotaxis-Navier-Stokes system is considered. It is known that for all suitably regular initial data, a corresponding initial-boundary value problem admits at least one global weak solution which can be obtained as the pointwise limit of a sequence of solutions to appropriately regularized problems. The present paper shows that after some relaxation time, this solution enjoys further regularity properties and thereby complies with the concept of eventual energy solutions which is newly introduced here, and which inter alia requires that two quasi-dissipative inequalities are ultimately satisfied. Moreover, it is shown that actually for any such eventual energy solution there exists a waiting time beyond which the solution is smooth and classical, and that a spatially homogeneous equilibrium is approached in the large time limit.