What actually Happens to EU Directives in the Member States? – A Cross-Country Cross-Sector View on National Transposition Instruments

This study empirically investigates the transposition patterns of EU directives in all 15 member states and in six major sectors of the economy with a view on analysing the political-economic reasons behind sector and national differences in the legal transposition instruments used. In particular, we model the influence of both national sector importance and governmental constellations on the ratio of primary to totally transposed EU directives. We find that government strength and net EU receipts negatively affect the ratio of primary to total transpositions. Economic sector size plays a positive significant role for primary transposition ratios. However, the direction of the effect changes if we control for other sector characteristics, i.e. sector lobbying potential and technicality.

Macroscopic Entanglement of a Bose Einstein Condensate on a Superconducting Atom Chip

We propose and analyse a practically implementable scheme to generate macroscopic entanglement of a Bose-Einstein condensate in a micro-magnetic trap magnetically coupled to a superconducting loop. We treat the superconducting loop in a quantum superposition of two different flux states coupled with the magnetic trap to generate macroscopic entanglement. Our scheme also provides a platform to realise interferometry of entangled atoms through the Bose-Einstein condensate and to explore physics at the quantum-classical interface.Comment: 4 Pages, Two figure

Photon Qubit is Made of Two Colors

Single particles of light can be prepared in a quantum superposition of two different colors, an achievement that could prove useful for quantum information processing

Light-Mediated Collective Atomic Motion in an Optical Lattice Coupled to a Membrane

We observe effects of collective atomic motion in a one-dimensional optical lattice coupled to an optomechanical system. In this hybrid atom-optomechanical system, the lattice light generates a coupling between the lattice atoms as well as between atoms and a micromechanical membrane oscillator. For large atom numbers we observe an instability in the coupled system, resulting in large-amplitude atom-membrane oscillations. We show that this behavior can be explained by light-mediated collective atomic motion in the lattice, which arises for large atom number, small atom-light detuning and asymmetric pumping of the lattice, in agreement with previous theoretical work. The model connects the optomechanical instability to a phase delay in the global atomic back-action onto the lattice light, which we observe in a direct measurement.Comment: new introduction, title and outlook; small modifications of the main text and figure

What actually happens to EU directives in the member states?: A cross-country cross-sector view on national transposition instruments

This study empirically investigates the transposition patterns of EU directives in all 15 member states and in six major sectors of the economy with a view on analysing the political-economic reasons behind sector and national differences in the legal transposition instruments used. In particular, we model the influence of both national sector importance and governmental constellations on the ratio of primary to totally transposed EU directives. We find that government strength and net EU receipts negatively affect the ratio of primary to total transpositions. Economic sector size plays a positive significant role for primary transposition ratios. However, the direction of the effect changes if we control for other sector characteristics, i.e. sector lobbying potential and technicality

Moritz Cantor: Vorlesungen über Geschichte der Mathematik. Rezensionen von Peter Treutlein im Jahrbuch über die Fortschritte der Mathematik / Zusammengestellt von Gabriele Dörflinger

Der Karlsruher Gymnasialprofessor Peter Treutlein (1845-1912) schrieb ab 1892 sämtliche Rezensionen zu Cantors Mathematikgeschichte im Jahrbuch über die Fortschritte der Mathematik. Im Gegensatz zu den Rezensionen Gustaf Eneströms geht Peter Treutlein nicht auf Einzelheiten ein und weist auch nicht auf Fehler hin. Seine Referate enden in der Regel mit dem Dank an Moritz Cantor

Does a large quantum Fisher information imply Bell correlations?

The quantum Fisher information (QFI) of certain multipartite entangled quantum states is larger than what is reachable by separable states, providing a metrological advantage. Are these nonclassical correlations strong enough to potentially violate a Bell inequality? Here, we present evidence from two examples. First, we discuss a Bell inequality designed for spin-squeezed states which is violated only by quantum states with a large QFI. Second, we relax a well-known lower bound on the QFI to find the Mermin Bell inequality as a special case. However, a fully general link between QFI and Bell correlations is still open.Comment: 4 pages, minor edit

Sequential quantum-enhanced measurement with an atomic ensemble

We propose a quantum-enhanced iterative (with $K$ steps) measurement scheme based on an ensemble of $N$ two-level probes which asymptotically approaches the Heisenberg limit $\delta_K \propto R^{-K/(K+1)}$, $R$ the number of quantum resources. The protocol is inspired by Kitaev's phase estimation algorithm and involves only collective manipulation and measurement of the ensemble. The iterative procedure takes the shot-noise limited primary measurement with precision $\delta_1\propto N^{-1/2}$ to increasingly precise results $\delta_K\propto N^{-K/2}$. A straightforward implementation of the algorithm makes use of a two-component atomic cloud of Bosons in the precision measurement of a magnetic field.Comment: 5 pages, 1 figur

Frequency-tunable microwave field detection in an atomic vapor cell

We use an atomic vapor cell as a frequency tunable microwave field detector operating at frequencies from GHz to tens of GHz. We detect microwave magnetic fields from 2.3 GHz to 26.4 GHz, and measure the amplitude of the sigma+ component of an 18 GHz microwave field. Our proof-of-principle demonstration represents a four orders of magnitude extension of the frequency tunable range of atomic magnetometers from their previous dc to several MHz range. When integrated with a high resolution microwave imaging system, this will allow for the complete reconstruction of the vector components of a microwave magnetic field and the relative phase between them. Potential applications include near-field characterisation of microwave circuitry and devices, and medical microwave sensing and imaging