Nanowerk July 11, 2020 Inspired by the ability of chameleons to change color by using temperature to direct the skin tissue that contains nanocrystals reflecting light, to expand or contract, an international team of researchers (USA – University of Chicago, University of South Carolina, University of North Texas, Cornell University, Argonne National Laboratory, Mexico, Turkey, Colombia) has developed a way to stretch and strain liquid crystals to generate different colors. They dispersed chiral droplets in polymer films and deformed it by inducing uniaxial or biaxial stretching. Their measurements are interpreted by resorting to simulations of the corresponding systems, thereby providing […]
New materials for extra thin computer chips
EurekAlert July 13, 2020 To realize the full potential of nanoelectronic devices based on 2D materials they have to be placed on the appropriate substrate, and an insulator layer is also needed on top of it, an insulator that is extremely thin and of extremely good quality. An international team of researchers (Austria, Russia, China, USA – UT Austin, Germany, Italy) has achieved excellent results with special crystals containing fluorine atoms. A transistor prototype with a calcium fluoride insulator has provided convincing data, and other materials are still being analysed. The new electrically conductive 2D materials can be combined with […]
New organic material unlocks faster and more flexible electronic devices
Science Daily July 15, 2020 Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications. By precisely stacking carbon and hydrogen molecules one over the other researchers in Australia have designed an organic semiconductor. The material is just one carbon atom thick which gives it the flexibility to be bent into any shape. The material is biodegradable or easily recyclable, thus avoiding the tonnes of e-waste generated by current generation electronic devices…read more. Open Access TECHNICAL ARTICLE
A new path for electron optics in solid-state systems
Science Daily July 14, 2020 Electron optics has been demonstrated mainly in one-dimensional devices, for example in nanotubes. Researchers in Switzerland have shown that the band inversion and hybridization present in two coupled semiconductor layers, consisting of InAs and GaSb system provide a novel transport mechanism that guarantees non-vanishing interference even when all angles of incidence occur. Through a combination of transport measurements and theoretical modelling, they found that their devices operate as a Fabry-Pérot interferometer in which electrons and holes form hybrid states. As the mechanism requires only band inversion and hybridization, the research opens engineering electron-optical phenomena in […]
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 […]
Scientists build high-performing hybrid solar energy converter
Science Daily July 15, 2020 A team of researchers in the US (UC San Diego, Tulane University, San Diego State University) has developed a hybrid solar energy converter that generates electricity and steam with high efficiency and low cost. It utilizes an approach that more fully captures the whole spectrum of sunlight. It generates electricity from high efficiency multi-junction solar cells that also redirect infrared rays of sunlight to a thermal receiver, which converts those rays to thermal energy. Energy can be stored until needed. In demonstrations it operated at 85.1 percent efficiency, delivered steam at up to 248°C, and […]
Seventy-Five Years After Trinity
Inside Science July 15, 2020 The Manhattan Project’s massive effort to build the first atomic bomb led to the Trinity test on July 16, 1945. The project had consumed huge amounts of resources in building weapons of unprecedented potency, gave godlike power to flawed humans. It also inspired innovations and actions that continue to cascade through science and culture in ways both predictable and surprising. The stories, videos and graphics collected here commemorate the 75th anniversary of Trinity and present a snapshot of how deeply the influence of the Manhattan Project has permeated science and culture. While we cannot possibly […]
Tiny bubbles make a quantum leap
EurekAlert July 13, 2020 An international team of researchers (USA – UC Berkeley, Columbia University, industry, Montana State University, Germany, Japan) found that placing sufficient strain in a 2D material–tungsten diselenide creates localized states that can yield single-photon emitters. The team was able to directly image these states for the first time, revealing that even at room temperature they are highly tunable and act as quantum dots, tightly confined pieces of semiconductors that emit light. Fully tunable, room-temperature single-photon emitters are now within our grasp, paving the way for controllable–and practical quantum photonic devices. These devices can be the foundation […]
UBCO researchers create liquid-repelling substance that works on all surfaces
EurekAlert July 15, 2020 Omniphobic–all-liquid repellent–films can repel a broad range of liquids, but the applicability of these coatings has always been limited to silicon wafers or smooth glass. Researchers in Canada have developed a facile procedure to generate an omniphobic coating on any surface, including metals, paper, ceramics, etc. The process involves depositing an ultra smooth, silicon wafer-like silica layer and then treating this layer with a highly reactive chlorosilane, which grafts polydimethylsiloxane chains onto the surface. Negligible contact angle hysteresis (≤1°) for various liquids, including ultralow surface tension oils, alcohols, and fluoro-solvents, was achieved on many different substrates […]
Underused part of the electromagnetic spectrum gets optics boost from metamaterial
Phys.org July 14, 2020 Terahertz radiation potentially has applications in next-generation wireless communications (6G/7G), security systems, biomedicine, etc. because of the lack of appropriate materials and sophisticated optical components for flexible control of terahertz waves. Researchers in Japan have engineered a 2.28-µm ultra-thin terahertz metasurface collimator with a high directivity of 4.6 times consisting of 339 pairs of meta-atoms compared with a single terahertz continuous-wave source. The metasurface exhibits an extremely high refractive index of 15.0 and a low reflectance of 15.5% at 3.0 THz. It should facilitate ground-breaking applications such as arbitrary phase converters, solid immersion lenses, and cloaking…read more. […]