31 research outputs found
Peter Leander Hofrichter, Logoslied, Gnosis und Neues Testament, (Theologische Texte und Studien 10) Hildesheim – Zürich – New York, Olms, 2003
No full textGrappe Christian. Peter Leander Hofrichter, Logoslied, Gnosis und Neues Testament, (Theologische Texte und Studien 10) Hildesheim – Zürich – New York, Olms, 2003. In: Revue d'histoire et de philosophie religieuses, 85e année n°3, Juillet-Septembre 2005. pp. 438-439
1990-1991: Inherit the Wind
No full textForeground: Jonathan Adams As Cates, Kenneth Albers as Drummond, Gregory Steres as Meeker, David Silvis as Dunlap, and Jeffrey Christian as Bollinger
Background: Thom Hofrichter as Jury (center) and Jack Lee as Cooper (on right)Inherit the Wind;Grayscal
Direct Probing of the Mott Crossover in the SU(N) Fermi-Hubbard Model
No full textWe report on a detailed experimental investigation of the equation of state (EoS) of the three-dimensional Fermi-Hubbard model (FHM) in its generalized SU(N)-symmetric form, using a degenerate ytterbium gas in an optical lattice. In its more common spin-1/2 form, the FHM is a central model of condensed-matter physics. The generalization to N>2 was first used to describe multi-orbital materials and is expected to exhibit novel many-body phases in a complex phase diagram. By realizing and locally probing the SU(N) FHM with ultracold atoms, we obtain model-free access to thermodynamic quantities. The measurement of the EoS and the local compressibility allows us to characterize the crossover from a compressible metal to an incompressible Mott insulator. We reach specific entropies above Néel order but below that of uncorrelated spins. Having access to the EoS of such a system represents an important step towards probing predicted novel SU(N) phases
Probing the SU(N) Fermi-Hubbard model with ytterbium atoms in an optical lattice
No full textThis thesis reports on the experimental realization of the 3D SU(N) Fermi-Hubbard model and the direct probing of the equation of state with an ultracold quantum gas of fermionic ytterbium in an optical lattice. Ultracold atoms in optical lattices constitute a flexible and highly tunable system to investigate Hamiltonians of condensed matter physics such as the Hubbard model. In particular, ytterbium atoms are ideal candidates for the realization of the Fermi-Hubbard model with SU(N)-symmetry due to a high decoupling of the nuclear spin from the electronic configuration. As a consequence of this enlarged symmetry, thermodynamic properties of the atomic sample depend on N, the number of spin components in the quantum gas, and novel, exotic phases are predicted to emerge at low temperatures.
By locally probing a quantum gas of 173Yb in a 3D optical lattice, we determine the equation of state of the SU(6) and SU(3) Fermi-Hubbard model. The measurement of the equation of state allows us to obtain direct, model-independent access to the thermodynamic quantities of the lattice gas. In this way, we can characterize the crossover from a Fermi liquid to an SU(N) Mott insulator when tuning the interaction strength, and can probe the compressibility of the quantum gas in different interaction regimes. Moreover, we find a low specific entropy of the SU(6) gas below that of
uncorrelated spins, indicating the presence of partial spin correlations in the atomic sample. The ability to access the equation of state of such high spin systems, as well as the low obtained entropy, represent an important step towards the realization of SU(N) spin Hamiltonians and the characterization of novel SU(N) phases.Diese Doktorarbeit beschreibt die experimentelle Umsetzung des 3D SU(N) Fermi-Hubbard Modells und die direkte Messung der Zustandsgleichung mit Hilfe eines ultrakalten Quantengases von fermionischen Ytterbium-Atomen in einem optischen Gitter. Ultrakalte, neutrale Atome in optischen Gittern stellen ein gut kontrollierbares und hochflexibles System dar um Modelle aus der Festkörperphysik, wie z.B. das Hubbard Modell, zu untersuchen. Insbesondere erlauben Ytterbium-Atome, diese Modelle mit SU(N) Symmetrie zu realisieren, da bei ihnen der Kernspin nahezu vollständig von der elektronischen Konfiguration der Atome entkoppelt ist. Als Folge dieser erweiterten Symmetrie hängen die thermodynamischen Größen von N – der Anzahl der Spinkomponenten im Quantengas – ab, und man erwartet neuartige Phasenzustände dieser Systeme bei niedrigen Temperaturen.
Durch Messen der lokalen Eigenschaften eines 173Yb Quantengases, erhalten wir die Zustandsgleichung des SU(6) und SU(3) Fermi-Hubbard Modells. Die Zustandsgleichung erlaubt es uns, direkten, modellunabhängigen Zugang zu den thermodynamischen Größen des Gases im Gitter zu erlangen. Hiermit ist es möglich, durch Ändern der Wechselwirkungsstärke den Übergang von einer Fermi-Flüssigkeit zu einem SU(N) Mott-Isolator zu beobachten, sowie die Kompressibilität des Gases für unterschiedlich starke Wechselwirkungen zu ermitteln. In dem Experiment beobachten wir eine niedrige spezifische Entropie des SU(6) Gases, niedriger als die von unkorrelierten Spins, was auf partielle Spinkorrelationen im Quantengas hinweist. Die Möglichkeit, die Zustandsgleichung solcher Systeme mit hohem Spin direkt zu bestimmen, sowie die niedrige Entropie die erzielt wurde, stellen einen wichtigen Schritt für die Realisierung von SU(N) Spin-Hamiltonoperatoren dar, sowie für die Charakterisierung von neuartigen SU(N) Phasenzuständen
Untersuchungen zu stereoselektiven Reduktionen ausgewählter α-substituierter β-Ketocarbonsäureester durch bio- und chemokatalytische Transformationen
No full textGegenstand der vorliegenden Arbeit war die Synthese von enantiomerenreinen α-substituierten β-Hydroxyestern zu neuartigen 4,5-disubstituieren Oxazolidin-2-onen, die auch als EVANS-Auxilare bekannt sind
Shear bond strength of different retainer wires and bonding adhesives in consideration of the pretreatment process
No full textIntroduction: We aimed to compare the shear bond strength (SBS) of three different retainer wires and three different bonding adhesives in consideration of the pretreatment process of enamel surface sandblasting. Methods: 400 extracted bovine incisors were divided into 10 groups of 20 paired specimens each. 10 specimens of each group were pretreated by enamel sandblasting. The retainer wires Bond-A-Braid (TM), GAC-Wildcat (R)-Twistflex and everStick (R) ORTHO were bonded to the teeth with the adhesives Transbond (TM)-LR, Tetric-EvoFlow (TM) and Stick (R) FLOW and then debonded measuring the SBS. Results: While sandblasting generally increased SBS for all tested combinations, the retainer wires bonded with Transbond (TM)-LR showed the highest SBS both with and without prior sandblasting. Significantly lower SBS were found for Tetric-EvoFlow (TM) that were comparable to those for everStick (R) ORTHO. Conclusions: Pretreatment of enamel surfaces by sandblasting increased the SBS of all retainer-wires. Transbond (TM)-LR showed the best results compared to Tetric-EvoFlow (TM) and everStick (R) ORTHO, while all combinations used provided sufficient bonding strengths for clinical use
