American Physical Society September 3, 2020 Ordinarily the transmission of light from a laser can be cut in half when obscured by such a nanoparticle, but the molecule’s presence causes 10% more light to be transmitted. With better control of the system, the molecule-nanoparticle combination could potentially become transparent to the laser. The effect could lead to optical switches in which light transmission would be controlled by single molecules. Researchers in Germany have demonstrated that the extinction cross section of a large gold nanoparticle can be substantially reduced—i.e., the particle becomes more transparent—if a single molecule is placed in its […]
Tag Archives: S&T Germany
Recognising fake images using frequency analysis
EurekAlert July 16, 2020 To date, deep-fake images have been analysed using complex statistical methods. Researchers in Germany converted the images into the frequency domain using the discrete cosine transform and express the image as the sum of many different cosine functions. Natural images consist mainly of low-frequency functions. The analysis has shown that images generated by GANs (Generative Adversarial Networks) exhibit artefacts in the high-frequency range. The researchers’ experiments showed that these artefacts do not only occur in GAN generated images. They are a structural problem of all deep learning algorithms. Frequency analysis is therefore an effective way to […]
New process enables lithium mining in Germany
Tech Xplore July 7, 2020 Considerable quantities of the element lithium are deeply hidden in rock formations below the Upper Rhine Trench: dissolved in salty thermal water reservoirs. Chile, Argentina, and Australia account for more than 80 percent of global production. Researchers in Germany have developed an environmentally friendly process to extract lithium from the existing infrastructure of geothermal plants, through which up to two billion liters of thermal water flow every year. There can be up to 200 milligrams per liter. The process involves filtering out the lithium ions from the thermal water and concentrated until lithium can be […]
Light from inside the tunnel
Nanowerk June 30, 2020 In their experiment researchers in Germany focused two ultrashort light pulses with different wavelengths and slightly different propagation directions onto a thin slab of glass. A time- and frequency-resolved analysis of the emerging light emission showed that the current associated with the quantum mechanical tunneling process itself creates an optical non-linearity. The findings significantly expand both the fundamental understanding of optical non-linearity in dielectric materials and its potential for applications in information processing and light-based material processing…read more. TECHNICAL ARTICLE
New quantum materials with unique properties
Nanowerk June 23, 2020 Researchers in Germany are working on a German Research Foundation funded project that focuses on novel physical phenomena of solids resulting from a particularly strong coupling between a material’s elastic properties and its electronic quantum phases. Based on the findings obtained, the researchers expect to produce new quantum materials with extraordinary properties and open the application potential resulting from interactions between mechanical and electronic properties…read more.
Broad spectrum: Novel hybrid material proves an efficient photodetector
Phys.org April 9, 2020 The MOF compound developed by researchers in Germany comprises an organic material integrated with iron ions. The MOF forms superimposed layers with semiconducting properties, which makes it potentially interesting for optoelectronic applications. They found that the light sensitivity was dependent on temperature and wavelength from 400 to 1,575 nanometers. The spectrum of radiation goes from ultraviolet to near infrared. As the bandgap in the material is very small, only very little light energy is required to induce the electricity. The performance of the detector can be improved by cooling the detector down to lower temperatures and […]
Innovative technologies for satellites
EurekAlert April 7, 2020 Researchers in Germany working on project INNOcube have developed two technologies, Skith and Wall#E, to further simplify architecture for small satellite. Skith (Skip the harness) eliminates the internal cabling of the satellite components by enabling data transmission with ultra-broadband radio. Wall#E (Fiber Reinforced Spacecraft Walls for Energy Storage) is a special fibre-reinforced structure that can store electrical energy and at the same time used as the supporting structure of the satellite. It contributes to a significant reduction in the mass and volume of a satellite while maintaining the same performance. A prototype is expected to be […]
Researchers catch light in a funnel
Phys.org March 27, 2020 Rather than being an unavoidable nuisance, non-Hermiticity can be precisely controlled and used for sophisticated applications. Researchers in Germany implemented a non-Hermitian photonic mesh lattice by tailoring the anisotropy of the inter-site coupling. The appearance of an interface results in a complete collapse of the entire eigenmode spectrum, leading to an exponential localization of all modes at the interface. Consequently, any light field within the lattice travels toward this interface, irrespective of its shape and input position. Based on this topological phenomenon, they demonstrated a highly efficient funnel for light. The light accumulation achieved by the […]
Research team presents novel transmitter for terahertz waves
Phys.org March 16, 2020 If you irradiate pure germanium with a short laser pulse, it takes several microseconds before the electrical charge in the semiconductor disappears. Only then can the crystals absorb the next laser pulse. Gallium-arsenide crystals only deliver relatively narrowband terahertz pulses and thus a restricted frequency range. Researchers in Germany used gold implanted germanium to present ultrabroadband (extending up to 70 THz) THz emission that is compatible with mode-locked fibre lasers operating at wavelengths of 1.1 and 1.55 μm with pulse repetition rates of 10 and 20 MHz, respectively. This result opens the possibility for the development of compact THz […]
Longest microwave quantum link
Phys.org March 5, 2020 Currently there are computers with a few dozen qubits, but several hundreds of thousands of them are almost impossible to accommodate in existing devices as they need to be cooled down to temperatures close to the absolute zero of -273,15 degrees Celsius. To connect two superconducting quantum chips to exchange superposition states between them with minimal decoherence researchers in Germany cooled the chips to a few hundredths of a degree above absolute zero and demonstrated that the quantum link can be sufficiently cooled down to reliably transmit quantum information between two quantum chips. They will report […]