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

Thin-disk laser pump schemes for large number of passes and moderate pump source quality

Novel thin-disk laser pump layouts are proposed yielding an increased number of passes for a given pump module size and pump source quality. These novel layouts result from a general scheme which bases on merging two simpler pump optics arrangements. Some peculiar examples can be realized by adapting standard commercially available pump optics simply by intro ducing an additional mirror-pair. More pump passes yield better efficiency, opening the way for usage of active materials with low absorption. In a standard multi-pass pump design, scaling of the number of beam passes brings ab out an increase of the overall size of the optical arrangement or an increase of the pump source quality requirements. Such increases are minimized in our scheme, making them eligible for industrial applicationsComment: 16 pages, 9 figure

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

Numerically accurate linear response-properties in the configuration-interaction singles (CIS) approximation

In the present work, we report an efficient implementation of configuration interaction singles (CIS) excitation energies and oscillator strengths using the multi-resolution analysis (MRA) framework to address the basis-set convergence of excited state computations. In MRA (ground-state) orbitals, excited states are constructed adaptively guaranteeing an overall precision. Thus not only valence but also, in particular, low-lying Rydberg states can be computed with consistent quality at the basis set limit a priori, or without special treatments, which is demonstrated using a small test set of organic molecules, basis sets, and states. We find that the new implementation of MRA-CIS excitation energy calculations is competitive with conventional LCAO calculations when the basis-set limit of medium-sized molecules is sought, which requires large, diffuse basis sets. This becomes particularly important if accurate calculations of molecular electronic absorption spectra with respect to basis-set incompleteness are required, in which both valence as well as Rydberg excitations can contribute to the molecule's UV/VIS fingerprint

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

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

Partitioning Quantum Chemistry Simulations with Clifford Circuits

Current quantum computing hardware is restricted by the availability of only few, noisy qubits which limits the investigation of larger, more complex molecules in quantum chemistry calculations on quantum computers in the near-term. In this work, we investigate the limits of their classical and near-classical treatment while staying within the framework of quantum circuits and the variational quantum eigensolver. To this end, we consider naive and physically motivated, classically efficient product ansatz for the parametrized wavefunction adapting the separable pair ansatz form. We combine it with post-treatment to account for interactions between subsystems originating from this ansatz. The classical treatment is given by another quantum circuit that has support between the enforced subsystems and is folded into the Hamiltonian. To avoid an exponential increase in the number of Hamiltonian terms, the entangling operations are constructed from purely Clifford or near-Clifford circuits. While Clifford circuits can be simulated efficiently classically, they are not universal. In order to account for missing expressibility, near-Clifford circuits with only few, selected non-Clifford gates are employed. The exact circuit structure to achieve this objective is molecule-dependent and is constructed using simulated annealing and genetic algorithms. We demonstrate our approach on a set of molecules of interest and investigate the extent of our methodology's reach. Empirical validation of our approach using numerical simulations shows a reduction of the qubit count of up to a 50\% at a similar accuracy as compared to the separable-pair ansatz.Comment: 12 pages, 9 figures plus 3 pages, 8 figures appendi