Phys.org October 1, 2021 Researchers in Germany have combined a fiber-laser system with multi-pass cells to create a laser with a combination of few-cycle pulses at high average power, pulse energy and repetition rate and with stable carrier envelope phase (CEP) operation. The system coherently combines eight amplifier channels. It emits 300-fs pulses that are then compressed down to the few-cycle regime using two multi-pass cells. The first multi-pass cell uses standard dielectric mirrors and the second cell uses metal-based mirrors. With further improvements, they hope to achieve less than 300 mrad of CEP noise. The laser system opens new […]
Tag Archives: S&T Germany
Triangular honeycombs: Physicists design novel quantum material
Nanowerk September 14, 2021 Using molecular beam techniques researchers in Germany succeeded in depositing a single layer of indium atoms as triangular lattice on a silicon carbide crystal as support resulting in indenene. The relevant electrons occupy free space in between the indium positions. Their charge fills the “negative” of the triangular indium lattice which is actually a honeycomb lattice. Unlike graphene, indenene needs not to be cooled down to ultra-low temperatures to manifest its properties as a topological insulator. The simple structure of indenene represents at the same time a challenge: as soon as the single layer of indium […]
Using ‘smart rust’ to mark objects unambiguously and tackle counterfeiting
Nanowerk June 16, 2021 An object can be recycled responsibly only if all raw materials and intermediate products used for manufacturing it is marked unambiguously using a tamper-proof method. Inspired by the variation of a musical ensemble yielding distinguishable overtones, researchers in Germany have developed a magnetic particle-based toolbox that provides more than 77 billion different magnetic codes, adjustable in one single particle, that can be read out unambiguously, easily, and quickly. The variation of the supraparticle composition alters their magnetic overtones. By minimizing magnetic interactions, customizable signals are spectrally decoded by the simple method of magnetic particle spectroscopy. The […]
Anti-reflective films: What high-tech can learn from plants
EurekAlert April 13, 2021 Rose petals have a matt and at the same time rich color. The outer tissue of its petals, the epidermis, consists of densely packed microstructures, additionally ribbed by nanostructures. With these structures, the rose manages to couple all incident light into the cells – only the colored light escapes again. Researchers in Germany combined micro- and nanostructure to develop an anti-reflective film that replicates the epidermis of rose petals. The film increases the yield of solar modules by up to ten percent. Posters, display panels, traffic signs, furniture, packaging, facades, and many other applications also benefit […]
Researchers first to link silicon atoms on surfaces
Nanowerk March 30, 2021 Researchers in Germany have demonstrated Si–Si bond formation on Au(111) and Cu(111) surfaces by using two different monomers, each containing two silicon functional groups (CH3SiH2 or SiH3) attached to an aromatic backbone, leading to polymeric disilenes that interact with the surface. A combination of experimental and theoretical studies corroborated the formation of covalent Si–Si bonds between the long, highly ordered polymer chains with high diastereoselectivity. The reactive Si=Si bonds formally generated via double dehydrogenative coupling were stabilized via covalent Si–surface interaction. This method could be used to develop a completely new strategy for molecular changes to […]
Wafer-thin nanopaper changes from firm to soft at the touch of a button
Science Daily March 24, 2021 Mimicking the sea cucumbers which adapt and strengthen their tissue so that their soft exterior immediately stiffens when attacked by predators, researchers in Germany have developed a mechanism to strengthen and stiffen a material using electric current. They developed cellulose nanofibrils/polymer nanopapers with tailor-made interactions by deposition of thin single-walled carbon nanotube electrode layers for Joule heating. Application of DC at specific voltages translates into significant electrothermal softening via dynamization and breakage of the thermo-reversible supramolecular bonds. The altered mechanical properties are reversibly switchable in power on/power off cycles. Currently a power source is needed […]
Dresden scientists help setting new standards for cutting-edge genetic research
Science Daily February 24, 2021 Over the course of the next five years, a team of researchers in Germany are working on a project funded by the German Research Foundation to shape international standards for the exchange of human omics data. The initial focus is on developing, harmonizing, and optimizing processes of data collection. To address the legal and ethical questions researchers are working closely with lawyers who specialize in national and international privacy regulations. They will use state-of-the-art HPC, Cloud and storage technologies to build a distributed infrastructure accessible for all interested researchers and clinicians. The platform will integrate […]
Spintronics: New production method makes crystalline microstructures universally usable
Science Daily February 23, 2021 Based on a recently developed method that allows the fabrication of freestanding monocrystalline YIG bridges on gadolinium-gallium-garnet, researchers in Germany have developed a process that allows the transfer of monocrystalline yttrium-iron-garnet microstructures onto virtually any kind of substrate. The bridges’ spans are detached from the substrate by a dry etching process and immersed in a watery solution. Using drop-casting, the immersed YIG platelets can be transferred onto the substrate of choice, where the structures finally can be reattached and, thus, be integrated into complex devices or experimental geometries. They demonstrated that the structures retain their […]
A sharper look at the interior of semiconductors
Science Daily February 17, 2021 To investigate complex, functional, nanoscopic structures of semiconductor devices researchers in Germany have developed an imaging procedure using extreme ultraviolet coherence tomography. It is based on optical coherence tomography used in ophthalmology. They demonstrated the method at a laser-driven broadband extreme ultraviolet radiation source, based on high-harmonic generation. They showed that, besides nanoscopic axial resolution, the spectral reflectivity of all layers in a sample can be obtained using algorithmic phase reconstruction. This provides localized, spectroscopic, material-specific information of the sample. The method can be applied in semiconductor production, lithographic mask inspection, or quality control of multilayer […]
New mathematical method for generating random connected networks
Science Daily February 10, 2021 Many natural and human-made networks, such as computer, biological or social networks have a connectivity structure that critically shapes their behavior. Existing algorithms that create connected networks with a specific number of connections for each node suffer from uncontrolled bias potentially compromising the conclusions of the study. Researchers in Germany have developed a new method for the random sampling of connected networks with a specified degree sequence considering both the case of simple graphs and that of loopless multigraphs. Their method builds on a recently introduced novel sampling approach that constructs graphs with given degrees […]