0000000000523714
AUTHOR
M. Seidl
Strictly correlated uniform electron droplets
We study the energetic properties of finite but internally homogeneous D-dimensional electron droplets in the strict-correlation limit. The indirect Coulomb interaction is found to increase as a function of the electron number, approaching the tighter forms of the Lieb-Oxford bound recently proposed by Räsänen [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.206406 102, 206406 (2009)]. The bound is satisfied in three-, two-, and one-dimensional droplets, and in the latter case it is reached exactly-regardless of the type of interaction considered. Our results provide useful reference data for delocalized strongly correlated systems, and they can be used in the development and testing…
Mode-coupling crossover in viscous toluene revealed by neutron and light scattering
The dynamics of supercooled toluene, studied in a GHz-THz range by incoherent neutron and depolarized light scattering, is found to be in full accord with mode coupling predictions. Around the susceptibility minimum, neutron spectra are wavenumber independent and proportional to light scattering data; the fast β-relaxation scaling law applies; amplitude and frequency diverge with power laws that extrapolate towards a crossover temperature Tc K.
Mie plasmon in polyhedral metal clusters
We study the dependence of the classical plasmon frequency on the symmetry of the metal cluster and show that all clusters with at least two three-fold axes have the same plasmon frequency as the spherical cluster, ωp/√3. In these cases the effect of the geometry will only appear in the spill-out correction and in other quantum mechanical corrections.
Semiclassical Methods for the Description of Large Metal Clusters
One of the most fascinating aspects of clusters is that they can be made arbitrarily large and therefore provide links between the microscopic and the macroscopic world. It is challenging to study how their physical properties change when going from atoms and small molecules to the bulk limit of condensed matter. But also the models and mathematical tools themselves, which are used in order to tackle the many-body problem, are an object of study for the theoretician. In particular, the question of how far quantum-mechanics must be carried with increasing size and where classical pictures become appropriate is of great interest. In this spirit, we discuss here some semiclassical methods for …
The 1.5GeV harmonic double-sided microtron at Mainz University
Abstract At the Institut fur Kernphysik of Mainz University a harmonic double-sided microtron (HDSM) has been built to extend the experimental capabilities for nuclear and particle physics experiments to higher excitation energies. This novel microtron variant accelerates the 0.855 GeV continuous wave (cw) electron beam of the established three-staged race track microtron (RTM) cascade MAMI B up to 1.5 GeV. It consists of two normal conducting linear accelerators (linacs) through which the electrons are guided up to 43 times by a pair of 90°-bending magnets at each end. For beam dynamical reasons the linacs operate at the harmonic frequencies of 4.90 and 2.45 GHz. The extended facility is c…
Effect of Impregnation and Activation Conditions of Al2O3/CuO Supported Monolith Catalysts in the Reduction of NO
Reduction of NO in the presence of CO and Ar was examined on two series of monolithic sheets carrying an active CuO/Al 2 O 3 layer. In the impregnation procedure the ratio of Al 2 O 3 to CuO was varied in a wide range. The texture of the layer and the dispersion of CuO therein was controlled by mercury porosimetry, scanning electron microscopy and secondary ion mass spectrometry (SIMS). It could be established that the surface concentration of CuO determined by SIMS measurements is the most decisive quantity of the catalyst correlating linearly with the conversion of NO.