Phys.org November 2, 2021 Researchers at UCLA have developed a computer-free, all-optical process for the reconstruction of holograms using diffractive networks, diffractive network is an all-optical processor composed of a set of spatially engineered diffractive surfaces that collectively compute a desired transformation of an input light field through light-matter-interaction and diffraction. The spatial features of a diffractive network are trained and optimized for a given task using deep learning in a computer. After the training is complete, the diffractive surfaces can be fabricated and assembled to form a physical network that can all-optically reconstruct an input hologram of an unknown […]
Earth’s orbit affects millennial climate variability
Phys.org November 2, 2021 The varying magnitude of millennial climate variability (MCV) was linked to orbitally paced glacial cycles over the past 800 kyr. The scarcity of a long-term integration of high-resolution continental and marine records hampers our understanding of the evolution and dynamics of MCV before the mid-Pleistocene transition. An international team of researchers (China, USA – Columbia University, Brown University, Switzerland, UK) has synthesized four centennial-resolved elemental time series, which they interpret as proxies for MCV, from North Atlantic, Iberian margin, Balkan Peninsula (Lake Ohrid) and Chinese Loess Plateau. The proxy records reveal that MCV was pervasive and persistent […]
Engineers invent ultra-fast manufacturing technology
Nanowerk November 3, 2021 Current printing techniques for printing soft electronics (PSE) are still facing long-lasting challenges in addressing the conflict between printing speed and performance. A team of researchers in the US (California Polytechnic State University, UC San Diego, University of South Florida, Carnegie Mellon University) has developed a new corona-enabled electrostatic printing (CEP) technique for ultra-fast roll-to-roll (R2R) manufacturing of binder-free multifunctional e-skins. CEP-printed graphene e-skins were demonstrated to possess an outstanding strain sensing performance. The binder-free feature of the CEP-assembled networks enables them to provide pressure sensitivity as low as 2.5 Pa and capability to detect acoustic […]
Keeping one step ahead of earthquakes
Phys.org November 3, 2021 According to the researchers in France AI has the potential to improve the accuracy and speed of early warning systems. Earthquake early warning (EEW) systems are evolving rapidly due to advances in computer power and network communication. They work by identifying the first signals generated by an earthquake rupture before the strongest shaking and tsunami reach populated areas. These signals follow the origin of the earthquake and can be recorded seconds before the seismic waves. Prompt elasto-gravity signal (PEGS) which was recently identified travels at the speed of light but is a million times smaller than […]
A new dimension in magnetism and superconductivity launched
Science Daily November 3, 2021 In recent studies the impact of curvilinear geometry enters various disciplines, ranging from solid-state physics over soft-matter physics, chemistry, and biology to mathematics. An international team of researchers (Germany, Austria) summarized the state of the art and prospects for future research in curvilinear solid-state systems exhibiting such fundamental cooperative phenomena as ferromagnetism, antiferromagnetism, and superconductivity. Highlighting the recent developments and current challenges in theory, fabrication, and characterization of curvilinear micro- and nanostructures, with emphasis on perspective research directions entailing new physics and to their strong application potential. They aim to cross the boundaries between the […]
A proactive approach to removing space junk
Phys.org October 29, 2021 Time-varying magnetic fields generate eddy currents in conductive materials with resulting forces and torques due to the interaction of the eddy currents with the magnetic field. This phenomenon has previously been used to induce drag to reduce the motion of objects as they pass through a static field or to apply force on an object in a single direction using a dynamic field. A team of researchers in the US (University of Utah, Lawrence Livermore National Laboratory, industry) has shown that manipulation, with six degrees of freedom, of conductive objects is possible by using multiple rotating […]
Researchers develop a tool to neutralize chemical weapons using rare-earth elements
Phys.org November 3, 2021 An international team of researchers (Canada, USA – industry) designed and synthesized a new MOF composed of the rare-earth metals yttrium and terbium, bound with an organic linker. They named the structure RE-CU-10 (RE = rare-earth, CU = Concordia University). According to the researchers the linker, a rectangular tetratopic pyrene-based ligand, has a particular core that interacts with ultraviolet light, producing an exceptionally reactive, though short-lived, oxygen species that causes a change in the chemical warfare agent sulfur mustard. In tests they found that the MOF effectively oxidized—and thereby detoxified—the chemical warfare agent simulant. The process […]
A superconducting silicon-photonic chip for quantum communication
Nanowerk November 1, 2021 A key element for achieving discrete-variable QKD is a single-photon detector. Researchers in China heterogeneously integrated, superconducting silicon-photonic chip. Harnessing the unique high-speed feature of the optical waveguide-integrated superconducting detector, they performed optimal Bell-state measurement (BSM) of time-bin encoded qubits generated from two independent lasers. The optimal BSM enables an increased key rate of measurement-device-independent QKD (MDI-QKD), which is immune to all attacks against the detection system and hence provides the basis for a QKD network with untrusted relays. Together with the time-multiplexed technique, they enhanced the sifted key rate by almost one order of magnitude. […]
Towards self-restoring electronic devices with long DNA molecules
Science Daily November 2, 2021 single-molecule conductance falls off sharply with the length of the molecule so that only extremely short stretches of DNA are useful for electrical measurements. Researchers in Japan achieved an unconventionally high conductivity with a long DNA molecule-based junction in a “zipper” configuration that also shows a remarkable self-restoring ability under electrical failure. The team used a 10-mer and a 90-mer DNA strand to form a zipper-like structure and attached them to either a gold surface or to the metal tip of a scanning tunneling microscope. The separation between the tip and the surface constituted the […]
Towards straintronics: Guiding excitons in 2D materials
Science Daily October 30, 2021 Strain engineering is a powerful tool in designing artificial platforms for high-temperature excitonic quantum devices. An international team of researchers (USA – City College of New York, Germany, Japan) has created excitonic wires, essentially one-dimensional channels for excitons in what is otherwise a two-dimensional semiconductor by depositing the atomically thin 2D crystal on top of a microscopically small wire they created a small, elongated dent in the two-dimensional material, slightly pulling apart the atoms in the two-dimensional crystal and inducing strain in the material. For excitons, this dent is much like a pipe and once trapped […]