Die neuen Hochschulprofessionellen in Europa: Ausdifferenzierung und Aufgaben im internationalen Vergleich

In den vergangenen zwei Jahrzehnten mussten europäische Universitäten eine Vielzahl verschiedens-ter Anforderungen und Wandlungen bewältigen. Neben der Autonomisierung der Universitäten ge-hörten dazu vor allem die fortgesetzte Expansion der Hochschulsysteme, die Implementation der Bologna-Reformen, die Internationalisierung von Lehre und Forschung sowie die Einführung neuer Mechanismen zur Steuerung und Regulierung des Hochschulsektors. Universitäten sehen sich durch diese Veränderungen einer gesteigerten Komplexität gegenüber, die ihnen nicht nur ein höheres Maß an Verantwortlichkeit für ihr eigenes Handeln auferlegt, sondern es auch notwendig macht, dass Universitäten in der Lage sind, reflektierte Entscheidungen zu treffen. Dies setzt wiederum vo-raus, dass sie über entsprechende personelle Kapazitäten verfügen bzw. solche Kapazitäten entwi-ckeln, die sie in die Lage versetzen, den gesteigerten Anforderungen gerecht zu werden

Theory of the n=2 levels in muonic deuterium

The present knowledge of Lamb shift, fine- and hyperfine structure of the $\mathrm{2S}$ and $\mathrm{2P}$ states in muonic deuterium is reviewed in anticipation of the results of a first measurement of several $\mathrm{2S-2P}$ transition frequencies in muonic deuterium ($\mu\mathrm{d}$). A term-by-term comparison of all available sources reveals reliable values and uncertainties of the QED and nuclear structure-dependent contributions to the Lamb shift, which are essential for a determination of the deuteron rms charge radius from $\mu\mathrm{d}$. Apparent discrepancies between different sources are resolved, in particular for the difficult two-photon exchange contributions. Problematic single-sourced terms are identified which require independent recalculation.Comment: 26 pages, add missing feynman diagrams (Fig. 3), renumber items (Tab. IV), correct a sum (column 5, Tab. IV

Optical resonances on sub-wavelength silver lamellar gratings

Copyright © 2008 Optical Society of America. This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=oe-16-26-22003 Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.The optical response of sub-wavelength silver lamellar gratings has been theoretically investigated. Two distinct types of resonance have been predicted for incident radiation with E-field perpendicular to the long axis of the wires. The first resonance has been identified as a cavity mode resonance that is associated with transmission enhancement. The second resonance has been identified as an entirely new horizontal plasmon resonance on the incident (and transmission) surfaces of the wires of the grating. Normal surface plasmon modes are investigated on discontinuous gratings, and their relation to those found on continuous gratings is highlighted by focusing on the perturbation effect of the discontinuities. It is shown that the new horizontal plasmon mode is in no way related to the well known diffractively coupled surface plasmon, and is shown to have a particle plasmon-like nature. It is therefore termed a horizontal particle plasmon, and may be either an uncoupled horizontal particle plasmon resonance (a 1-dimensional particle plasmon) or a coupled horizontal particle plasmon resonance (a 2-dimensional particle plasmon) depending on the height of the grating. It is shown that this resonance may result in a reflection efficiency that is very high, even when the grating would be optically thin if it were a homogeneous film, therefore, it behaves as an inverse wire grid polariser as it reflects more TM than TE incident radiation

Photoemission Electron Microscopy as a tool for the investigation of optical near fields

Photoemission electron microscopy was used to image the electrons photoemitted from specially tailored Ag nanoparticles deposited on a Si substrate (with its native oxide SiO$_{x}$). Photoemission was induced by illumination with a Hg UV-lamp (photon energy cutoff $\hbar\omega_{UV}=5.0$ eV, wavelength $\lambda_{UV}=250$ nm) and with a Ti:Sapphire femtosecond laser ($\hbar\omega_{l}=3.1$ eV, $\lambda_{l}=400$ nm, pulse width below 200 fs), respectively. While homogeneous photoelectron emission from the metal is observed upon illumination at energies above the silver plasmon frequency, at lower photon energies the emission is localized at tips of the structure. This is interpreted as a signature of the local electrical field therefore providing a tool to map the optical near field with the resolution of emission electron microscopy.Comment: 10 pages, 4 figures; submitted to Physical Review Letter

Lamb shift in muonic helium ion

The Lamb shift (2P_{1/2}-2S_{1/2}) in the muonic helium ion (mu ^4_2He)^+ is calculated with the account of contributions of orders alpha^3, alpha^4, alpha^5 and alpha^6. Special attention is given to corrections of the electron vacuum polarization, the nuclear structure and recoil effects. The obtained numerical value of the Lamb shift 1379.028 meV can be considered as a reliable estimate for the comparison with experimental data.Comment: 18 pages, 11 figure

Retardation-induced plasmon resonances in coupled nanoparticles

We study the coupling induced by retardation effects when two plasmon-resonant nanoparticles are interacting. This coupling leads to an additional resonance, the strength of which depends on a subtle balance between particle separation and size. The scattering cross section and the near field associated with this coupled resonance are studied for cylindrical particles in air and in water. Implications for surface-enhanced Raman scattering and nano-optics are discussed. (C) 2001 Optical Society of America

Quantum computer-aided design of quantum optics hardware

The parameters of a quantum system grow exponentially with the number of involved quantum particles. Hence, the associated memory requirement to store or manipulate the underlying wavefunction goes well beyond the limit of the best classical computers for quantum systems composed of a few dozen particles, leading to serious challenges in their numerical simulation. This implies that the verification and design of new quantum devices and experiments are fundamentally limited to small system size. It is not clear how the full potential of large quantum systems can be exploited. Here, we present the concept of quantum computer designed quantum hardware and apply it to the field of quantum optics. Specifically, we map complex experimental hardware for high-dimensional, many-body entangled photons into a gate-based quantum circuit. We show explicitly how digital quantum simulation of Boson sampling experiments can be realized. We then illustrate how to design quantum-optical setups for complex entangled photonic systems, such as high-dimensional Greenberger-Horne-Zeilinger states and their derivatives. Since photonic hardware is already on the edge of quantum supremacy and the development of gate-based quantum computers is rapidly advancing, our approach promises to be a useful tool for the future of quantum device design

Plasmon resonant coupling in metallic nanowires

We investigate the plasmon resonances of interacting silver nanowires with a 50 nm diameter. Both non-touching and intersecting configurations are investigated. While individual cylinders exhibit a single plasmon resonance, we observe uch ore complex spectra of resonances for interacting structures. The number and magnitude of the different resonances depend on the illumination direction and on the distance between the particles. For very small separations, we observe a dramatic field enhancement between the particles, where the electric field amplitude reaches a hundredfold of the illumination. A similar enhancement is observed in the grooves created in slightly intersecting particles. The topology of these different resonances is related to the induced polarization charges. The implication of these results to surface enhanced Raman scattering (SERS) are discussed. (C) 2001 Optical Society of America