Manipulating superconducting plasma waves with terahertz light
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- Written by Max-Planck-Institut für Struktur und Dynamik der Materie
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Terahertz illumination amplifies Josephson plasma waves in high temperature superconductors, potentially paving the way for stabilizing fluctuating superconductivity
Most systems in nature are inherently nonlinear, meaning that their response to any external excitation is not proportional to the strength of the applied stimulus. Nonlinearities are observed, for example, in macroscopic phenomena such as the flow of fluids like water and air or of currents in electronic circuits. Manipulating the nonlinear behavior is therefore inherently interesting for achieving control over several processes. An international team of researchers led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter at CFEL in Hamburg utilized the nonlinear interaction between a terahertz light field and a superconducting plasma wave in a high temperature cuprate superconductor to amplify the latter. This resulted in a more coherent superconductor, which is less susceptible to thermal fluctuations. Due to the non-dissipative superconducting nature of the plasma wave, the study opens up new avenues for “plasmonics”, a field of science utilizing plasma waves for transmitting information. These findings are reported in the journal Nature Physics.
A signal boost for molecular microscopy
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- Written by Max-Planck-Institut für Quantenoptik
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Cavity-enhanced Raman-scattering reveals information on structure and properties of carbon nanotubes. The inherently weak signals are amplified by using special micro cavities as resonator, giving a general boost to Raman spectroscopy as a whole.
Quantum matter without memory loss
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- Written by Max-Planck-Institut für Quantenoptik
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MPQ scientists obtain evidence of many-body localization in a closed quantum system.
During equilibration ordinary many-body systems lose all information about the initial state. Every morning we experience an example for this behaviour. Milk poured into a cup of coffee mixes perfectly and after some time it is impossible to say how exactly the two fluids were put together. The same behaviour holds for almost all quantum systems. However, recently a new phenomenon called “many-body localization” has been predicted theoretically, which allows well insulated quantum systems to preserve memory of the initial state forever. Now a team of scientists around Dr. Christian Groß and Professor Immanuel Bloch (Director at MPQ and Chair of Quantum Optics at LMU Munich), in cooperation with David Huse (Princeton University), has obtained evidence of such a behaviour in a two-dimensional quantum system of cold rubidium atoms trapped in an optical lattice (Science, 24 June 2016).
Quantum processor for single photons
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- Written by Max-Planck-Institut für Quantenoptik
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MPQ-scientists have realised a photon-photon logic gate via a deterministic interaction with a strongly coupled atom-resonator system.
"Nothing is impossible!" In line with this motto, physicists from the Quantum Dynamics Division of Professor Gerhard Rempe (director at the Max Planck Institute of Quantum Optics) managed to realise a quantum logic gate in which two light quanta are the main actors. The difficulty of such an endeavour is that photons usually do not interact at all but pass each other undisturbed. This makes them ideal for the transmission of quantum information, but less suited for its processing. The scientists overcame this steep hurdle by bringing an ancillary third particle into play: a single atom trapped inside an optical resonator that takes on the role of a mediator. “The distinct feature of our gate implementation is that the interaction between the photons is deterministic”, explains Dr. Stephan Ritter. “This is essential for future, more complex applications like scalable quantum computers or global quantum networks.” (Nature, Advance Online Publication, 6 July 2016, DOI: 10.1038/nature18592).
A drop of water as a model for the interplay of adhesion and stiction
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- Written by Universität Zürich
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Physicists at the University of Zurich have developed a system that enables them to switch back and forth the adhesion and stiction (static friction) of a water drop on a solid surface. The change in voltage is expressed macroscopically in the contact angle between the drop and the surface. This effect can be attributed to the change in the surface properties on the nanometer scale.
3D printed optical lenses, hardly larger than a human hair
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- Written by Universität Stuttgart
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3D printing enables the smallest complex micro-objectives
3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines are written sequentially, even the most complex devices could be realized fast and easy. This method is now also available for optical elements. Researchers at University of Stuttgart in Germany have used an ultrashort laser pulses in combination with optical photoresist to create optical lenses which are hardly larger than a human hair.
First experimental quantum simulation of particle physics phenomena
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- Written by Universität Innsbruck,
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Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.
Information Technology Agreement of the WTO comes into force on 1st July 2016
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- Written by Christopher Griesbeck
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The World Trade Organization (WTO) expanded its Information Technology Agreement (ITA) which will come into force on 1 July 2016. The EU and 24 other countries, including Japan, China and the USA, will gradually eliminate custom duties on 201 different IT-products till 2019.
Scientists discover mechanism of thalidomide (Contergan)
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- Written by Technische Universität München
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In the 1950s, thalidomide (Contergan) was prescribed as a sedative drug to pregnant women, resulting in a great number of infants with serious malformations. Up to now, the reasons for these disastrous birth defects have remained unclear. Researchers at the Technical University of Munich (TUM) have at last identified the molecular mechanism of thalidomide. Their findings are highly relevant to current cancer therapies, as related substances are essential components of modern cancer treatment regimens.
High yield at high selectivity – lentiviral vectors with Nipah envelope proteins developed
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- Written by Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel
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To transfer genes exclusively into the patient’s therapy relevant cells is in the focus of current research approaches in gene therapy. Researchers of the Paul-Ehrlich-Institut have succeeded in modifying envelope proteins of Nipah virus (NiV) and to combine them with lentiviruses in such a way that they can now be used for a highly selective and efficient gene transfer to selected cells. Another advantage of these new vectors is that they can be produced at higher yields, which is required for clinical applications. PLOS Pathogens reports on these research results in its online edition of 09.06.2016.
Dentin nanostructures – a super-natural phenomenon
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- Written by Charité – Universitätsmedizin Berlin
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Why it is superior to any synthetic filling material at making teeth last
Dentin is one of the most durable biological materials in the human body. Researchers from Charité – Universitätsmedizin Berlin were able to show that the reason for this can be traced to its nanostructures and specifically to the interactions between the organic and inorganic components. Measurements performed at BESSYII, the Helmholtz-Zentrum Berlin's synchrotron radiation source, showed that it is the mechanical coupling between the collagen protein fibers and mineral nanoparticles which renders dentin capable of withstanding extreme forces. Results from this research have been recently published in the journal Chemistry of Materials*.
Process monitoring with laser speckle photometry – fast, accurate, non-contact, non-destructive
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- Written by Fraunhofer-Institut für Keramische Technologien und Systeme IKTS
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The Laser Speckle Photometry (LSP) is a novel method for in-line monitoring of industrial processes and was developed at Fraunhofer IKTS. The robust and cost-effective system analyzes surface properties and draws conclusions on geometry, porosity, or surface defects of a variety of materials. From June 13 to 17, 2016, the system will be presented at the World Conference on Non-Destructive Testing (WCNDT).
One impurity to bind them all
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- Written by Max-Planck-Institut für Quantenoptik
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MPQ researchers show that a single atomic impurity is able to trap infinitely many bosons around it.
Nobody is perfect, but sometimes it is the defect that makes the difference. For example, the electric properties of semiconductors undergo significant changes by the slightest variation in the dopant concentration, and though a perfect diamond is without any colour, atomic impurities make them shine in pale blue, violet or pink which even enhances their value. All these effects go back to processes that are triggered by the interaction of the impurity with the quantum many-body system it is embedded in. A team of physicists in the Theory Division of Prof. Ignacio Cirac at the Max Planck Institute of Quantum Optics (MPQ) has now investigated the more general case where an impurity atom is coupled to a structured bath of bosons (for example, photons in a periodically engineered dielectric) showing how a single atom can bind many bosons around it. Bound states of bosons are of particular interest because they give rise to long and strong interactions enabling new regimes for quantum simulations. (Phys. Rev. X 6, 021027 (2016), 25 May 2016).
Laser-manufactured customized lenses
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- Written by Fraunhofer-Institut für Lasertechnik ILT
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The Fraunhofer Institute for Laser Technology ILT is presenting selected project results in the areas of laser material processing of glass optics and packaging at the 13th Optatec international trade fair in Frankfurt from June 7 to 9, 2016. Highlights include the freeformOPT software that can be used to calculate individual free-form optics, as well as new laser processes for shaping, polishing, structuring and assembling fused silica optics.
Laser pulses: conductors for protons
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- Written by Max-Planck-Institut für Quantenoptik
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Using ultrashort laser pulses an international team at the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität Munich has managed to manipulate the positions of atoms in hydrocarbon molecules.
Surface wetting – tracking down the causes of polar hydrophobicity
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- Written by Fraunhofer-Institut für Werkstoffmechanik IWM
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The question of whether a liquid beads or adheres to a surface plays a role in almost all branches of industry. Researchers from the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg and ExxonMobil Research & Engineering in New Jersey have now developed a multiscale simulation method for predicting the wetting behavior of liquids on surfaces. In a recent edition of the Journal of the American Chemical Society, the research team applied this methodology to the previously unexplained phenomenon of polar hydrophobicity in fluorinated carbon surfaces.