Experimental challenges for high-mass matter-wave interference with nanoparticles

We discuss recent advances towards matter-wave interference experiments with free beams of metallic and dielectric nanoparticles. They require a brilliant source, an efficient detection scheme and a coherent method to divide the de Broglie waves associated with these clusters: We describe an approach based on a magnetron sputtering source which ejects an intense cluster beam with a wide mass dispersion but a small velocity spread of 10%. The source is universal as it can be used with all conducting and many semiconducting or even insulating materials. Here we focus on metals and dielectrics with a low work function of the bulk and thus a low cluster ionization energy. This allows us to realize photoionization gratings as coherent matter-wave beam splitters and also to realize an efficient ionization detection scheme. These new methods are now combined in an upgraded Talbot-Lau interferometer with three 266 nm depletion gratings. We here describe the experimental boundary conditions and how to realize them in the lab. This next generation of near-field interferometers shall allow us to soon push the limits of matter-wave interference to masses up to 10 megadaltons.Comment: 10 pages, 5 figure

Colloquium: Quantum interference of clusters and molecules

We review recent progress and future prospects of matter wave interferometry with complex organic molecules and inorganic clusters. Three variants of a near-field interference effect, based on diffraction by material nanostructures, at optical phase gratings, and at ionizing laser fields are considered. We discuss the theoretical concepts underlying these experiments and the experimental challenges. This includes optimizing interferometer designs as well as understanding the role of decoherence. The high sensitivity of matter wave interference experiments to external perturbations is demonstrated to be useful for accurately measuring internal properties of delocalized nanoparticles. We conclude by investigating the prospects for probing the quantum superposition principle in the limit of high particle mass and complexity.Comment: 19 pages, 13 figures; v2: corresponds to published versio

Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics

The atmospheric greenhouse effect, an idea that many authors trace back to the traditional works of Fourier (1824), Tyndall (1861), and Arrhenius (1896), and which is still supported in global climatology, essentially describes a fictitious mechanism, in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature it is taken for granted that such mechanism is real and stands on a firm scientific foundation. In this paper the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that (a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33 degrees Celsius is a meaningless number calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiative balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.Comment: 115 pages, 32 figures, 13 tables (some typos corrected

Three-Dimensional Maps of All Chromosomes in Human Male Fibroblast Nuclei and Prometaphase Rosettes

Studies of higher-order chromatin arrangements are an essential part of ongoing attempts to explore changes in epigenome structure and their functional implications during development and cell differentiation. However, the extent and cell-type-specificity of three-dimensional (3D) chromosome arrangements has remained controversial. In order to overcome technical limitations of previous studies, we have developed tools that allow the quantitative 3D positional mapping of all chromosomes simultaneously. We present unequivocal evidence for a probabilistic 3D order of prometaphase chromosomes, as well as of chromosome territories (CTs) in nuclei of quiescent (G0) and cycling (early S-phase) human diploid fibroblasts (46, XY). Radial distance measurements showed a probabilistic, highly nonrandom correlation with chromosome size: small chromosomes—independently of their gene density—were distributed significantly closer to the center of the nucleus or prometaphase rosette, while large chromosomes were located closer to the nuclear or rosette rim. This arrangement was independently confirmed in both human fibroblast and amniotic fluid cell nuclei. Notably, these cell types exhibit flat-ellipsoidal cell nuclei, in contrast to the spherical nuclei of lymphocytes and several other human cell types, for which we and others previously demonstrated gene-density-correlated radial 3D CT arrangements. Modeling of 3D CT arrangements suggests that cell-type-specific differences in radial CT arrangements are not solely due to geometrical constraints that result from nuclear shape differences. We also found gene-density-correlated arrangements of higher-order chromatin shared by all human cell types studied so far. Chromatin domains, which are gene-poor, form a layer beneath the nuclear envelope, while gene-dense chromatin is enriched in the nuclear interior. We discuss the possible functional implications of this finding

Research campaign : macroscopic quantum resonators (MAQRO)

The objective of the proposed macroscopic quantum resonators (MAQRO) mission is to harness space for achieving long free-fall times, extreme vacuum, nano-gravity, and cryogenic temperatures to test the foundations of physics in macroscopic quantum experiments at the interface with gravity. Developing the necessary technologies, achieving the required sensitivities and providing the necessary isolation of macroscopic quantum systems from their environment will lay the path for developing novel quantum sensors. Earlier studies showed that the proposal is feasible but that several critical challenges remain, and key technologies need to be developed. Recent scientific and technological developments since the original proposal of MAQRO promise the potential for achieving additional science objectives. The proposed research campaign aims to advance the state of the art and to perform the first macroscopic quantum experiments in space. Experiments on the ground, in micro-gravity, and in space will drive the proposed research campaign during the current decade to enable the implementation of MAQRO within the subsequent decade

Vollständig monolithisch integrierte X-Band Verstärker mit frequenz-selektiver Rückkopplung

The thesis addresses the design of monolithically integrated radio frequency amplifiers for X-band applications. The focus is on low-voltage low-noise amplifiers and efficient power amplifiers with high output power level. The challenge here is to realize stable amplifiers with remarkable performance metrics at low supply voltages. The general approach for stabilization amplifiers in the above frequency range is the use of a cascode topology which, however, requests higher supply voltages then single transistor operation. By using a special passive frequency-selective feedback, the use of the cascode topology could be avoided, and the amplifiers are stabilized over the entire frequency spectrum. Simultaneously, this feedback is used to neutralize the intrinsic feedback of the transistor at operating frequencies. As a result, a frequency dependent performance degeneration of the transistor can be mitigated. This work describes the influence of the passive frequency-selective feedback. Its usage as well its limitation are explained using the examples of a realized low noise amplifier and different power amplifiers. Further, the design of radio frequency amplifiers at X-band frequencies that employs silicon-germanium heterojunction bipolar transistors is described. All amplifiers were either incorporated in a 0.25 µm SiGe:C BiCMOS technology or in a 0.35 µm SiGe:C bipolar technology. The main achievements of this work include: - A 8.7 GHz narrow-band low noise amplifier incorporated in a 0.35 µm SiGe bipolar technology. The noise figure is 2.2 dB and the gain 28 dB at a supply voltage of 3 V. The low noise amplifier was subsequently used for a design of a double-balanced I/Q mixer. - Two packaged high efficient power amplifiers operating at a center frequency of 12 GHz. They are incorporated in a 0.35 µm SiGe bipolar technology. One amplifier uses a transformer-based output matching network and achieves 30.9 % of power-added efficiency and 23.9 dBm of maximum output power at a supply voltage of 1.8 V. The second amplifier utilizes an LC-balun for impedance matching at the output and a power-added-efficiency of 38 % at 1.8 V is measured. The maximum output power was 23.4 dBm. - A power amplifier in a 0.35 µm SiGe bipolar technology that uses power combining techniques to achieve 30 dBm (1 W) and 30 % of power-added efficiency at 10 GHz and 2 V supply voltage. - Two power amplifiers, incorporated in a 0.25 µm SiGe:C BiCMOS technology, demonstrating the capability of a non-advanced SiGe process to be used for radio frequency power applications. Power combining techniques, the use of the passive frequency-selective feedback and layout optimization enables the realization of power amplifiers which exhibit an output power of 30 dBm and a power-added efficiency of 35 % at supply voltages lower as 2.6 V.Die Dissertation beschäftigt sich mit der Entwicklung von monolithisch integrierten Hochfrequenzverstärkern für X-Band Anwendungen. Der Schwerpunkt liegt dabei auf rauscharmen Niederspannungs-Verstärkern und effizienten Leistungsverstärkern mit hoher Ausgangsleistung. Die Herausforderung hierbei ist es stabile Verstärker mit markanten Leistungswerten bei niedrigen Versorungsspannungen zu realisieren. Der allgemeine Ansatz zur Stabilisierung von Verstärkern im genannten Frequenzbereich erfolgt über die Verwendung einer Kaskode, welche jedoch höhere Versorungsspannung benötigt als der Einsatz eines einzelnen Einzeltransistor. Durch den Einsatz einer speziellen passiven frequenzselektiven Rückkopplung konnte die Verwendung einer Kaskoden-Topologie vermieden werden und die Verstärker werden über das gesamte Frequenzspektrum stabilisiert. Gleichzeitig ermöglicht die eingesetzte Rückkopplung eine Neutralisierung der intrinischen Rückkopplung des Transistors. Infolgedessen kann die frequenzbedingte Leistungsverschlechterung des Transistors abgeschwächt werden. Diese Arbeit beschreibt den Einfluss der passiven frequenzselektiven Rückkopplung. Ihre Verwendung als auch ihre Anwendungsgrenzen werden anhand eines realisierten rauscharmen Verstärkers und verschiedenen Leistungsverstärkern erklärt. Weiterhin wird der Entwurf von Hochfrequenzverstärkern für X-Band Frequenzen erläutert, die Siliciumgermanium Heterostruktur-Bipolartransistor verwenden. Alle Verstärker wurden entweder in einer 0.25 µm SiGe:C BiCMOS-Technologie oder in einer 0.35 µm SiGe:C Bipolar-Technologie realisiert. Wichtige Ergebnisse, die in dieser Arbeit enthalten sind: - Ein 8.7 GHz schmalbandiger rauscharmer Verstärker, welcher in einer 0.35 µm SiGe Bipolar-Technologie gefertigt wurde. Die Rauschzahl beträgt 2.2 dB und die maximale Verstärkung 28 dB bei einer Versorgungsspannung von 3 V. Dieser Verstärker wurde im Anschluss für das Design eines doppelt-symmetrischen Mischers verwendet. - Zwei hoch effiziente und gehäuste Leistungsverstärker, welche bei einer Mittenfrequenz von 12 GHz betrieben werden. Sie wurden in einer 0.35 µm SiGe Bipolar-Technologie realisiert. Ein Leistungsverstärker verwendet als Ausgangsanpassnetzwerk einen Transformator und erreicht einen Leistungswirkungsgrad von 31.5 % und eine Ausgangsleistung von 23.9 dBm bei einer Versorungsspannung von 1.8 V. Der zweite Verstärker verwendet zur Impedanzanpassung einen LC-Balun am Ausgang und es wurde ein Leistungswirkungsgrad 37.9 % bei 1.8 V gemessen. Die maximale Ausgangsleistung betrug 23.4 dBm. - Ein Leistungsverstärker in einer 0.35 µm SiGe Bipolar-Technologie welcher durch Leistungskombinierung eine Ausgangsleistung von 30 dBm (1 W)und einen Leistungswirkungsgrad von 30 % erreicht. Die Versorgungspannung liegt bei 2 V. Zwei Leistungsverstärker, gefertigt in einer 0.25 µm SiGe:C BiCMOS-Technologie, demonstrieren die Möglichkeit einen weniger fortschrittlichen SiGe-Prozesses für Hochfrequenz-Leistungsanwendungen zu verwenden. Leistungskombinierung, die Verwendung der passiven frequenzselektiven Rückkopplung und Layoutoptimierung ermöglichten die Realisierung von Leistungsverstärkern mit 30 % Ausgangsleistung und einem Leistungswirkungsgrad von 35 % bei Versorgungsspannungen unter 2.6 V

Mannan oligosaccharide prepartum supplementation: effects on dairy cow colostrum quality and quantity

Providing the neonatal calf with a sufficient quantity and quality of colostrum may optimise future health, performance and reduce the risk of morbidity. A 6-month double blind trial with 80 prepartum dairy cows was conducted to determine if supplementation with mannan oligosaccharide (MOS) influences colostrum quality, quantity and subsequent calf performance. The Holstein cross Friesian 80 cows (no heifers) were allocated into a control and treatment group at the point of drying off by previous lactation number and yield. The control and treatment group were fed the same commercial standard dry cow diet throughout the trial supplemented with a mineral concentrate without or with 1.33% MOS, respectively. Cows were milked out of colostrum within 40 min of calving prior to calf suckling, weight was recorded. Mannan oligosaccharide fed cows produced significantly more colostrum on first milking (7.5 kg, SEM±0.69) compared with cows fed without MOS (5.6 kg, SEM±0.43). The immunoglobulin G (IgG) concentrations (control 53.7 IgG g/l, SEM±5.8 and MOS of 42.7 IgG g/l, SEM±4.9) and total mass of IgG did not differ between treatments. No significant observable MOS-derived effect on calf health or weight gain occurred during the study

Matter-wave interference of particles selected from a molecular library with masses exceeding 10 000 amu

The quantum superposition principle, a key distinction between quantum physics and classical mechanics, is often perceived as a philosophical challenge to our concepts of reality, locality or space-time since it contrasts with our intuitive expectations with experimental observations on isolated quantum systems. While we are used to associating the notion of localization with massive bodies, quantum physics teaches us that every individual object is associated with a wave function that may eventually delocalize by far more than the body's own extension. Numerous experiments have verified this concept at the microscopic scale but intuition wavers when it comes to delocalization experiments with complex objects. While quantum science is the uncontested ideal of a physical theory, one may ask if the superposition principle can persist on all complexity scales. This motivates matter–wave diffraction and interference studies with large compounds in a three-grating interferometer configuration which also necessitates the preparation of high-mass nanoparticle beams at low velocities. Here we demonstrate how synthetic chemistry allows us to prepare libraries of fluorous porphyrins which can be tailored to exhibit high mass, good thermal stability and relatively low polarizability, which allows us to form slow thermal beams of these high-mass compounds, which can be detected using electron ionization mass spectrometry. We present successful superposition experiments with selected species from these molecular libraries in a quantum interferometer, which utilizes the diffraction of matter–waves at an optical phase grating. We observe high-contrast quantum fringe patterns of molecules exceeding a mass of 10000 amu and having 810 atoms in a single particle