EurekAlert January 22, 2021 Researchers in South Korea have developed a device using nanostructures that is capable of encrypting full-color images depending on the polarization of light. The on and off states can be adjusted according to the polarization of the incident light. It displays full-color images during the on state and shows no images in the off state and it can switch between different images. According to the researchers this feature can be utilized as an anti-forgery device security label that appears to be a simple color image to the naked eye but reveals the serial number when a […]
Experimental evidence of an intermediate state of matter between a crystal and a liquid
EurekAlert January 19, 2021 Researchers in Russia present a detailed analysis of their experimental study, which shows clear evidence of a two-stage melting process of a quasi-two-dimensional dusty plasma system in a high-frequency gas discharge. They accurately calculated global parameters of the orientational and translational order, as well as their susceptibilities to determine two critical points, related to “solid-to-hexatic” and “hexatic-to-liquid” phase transitions. The nature of the emerging defects and changes in their mutual concentration, in addition to the estimate of core energy of free dislocations also counts in favor of the formation of an intermediate hexatic phase. These results […]
Iceland Genetically Sequences Every COVID-19 Case in World-Leading Strategy
Science Alert January 17, 2021 Researchers at the biopharma group deCODE Genetics’ laboratory in Iceland have analyzed all the around 6,000 COVID-19 cases reported in Iceland making it the world leader in COVID sequencing. They have identified 463 separate variants – which scientists call haplotypes. Authorities have used the sequencing information to decide on precise, targeted measures to curb the spread of the virus. South African variant has not been detected in Iceland, 41 people have been identified as carriers of the British variant. If there are differences between viruses with the various pattern mutations, they are not obvious. While […]
The long-range transport of deconfined magnetic hedgehogs
Phys.org January 18, 2021 Using magnetic insulators to achieve long-range transport of spins has proved highly challenging. Researchers at UCLA resorted to topological spin textures rather than spins themselves for the purpose of long-range transport. The magnetic hedgehog is one type of topologically protected spin texture that generically exits in three-dimensional magnets. The researchers showed that the hedgehog current is a well conserved quantity and can be explored to achieve long-range transport in magnetic insulators. The study is based on the theoretical construct topological conservation law, which allowed the researchers to leverage the idea of hydrodynamics of topological spin textures. […]
Mysterious, Upside-Down Lightning May Not Be a Freak Phenomenon After All
Science Alert January 21, 2021 Lightning-like blue jets of atmospheric electric discharges fan into cones as they propagate from the top of thunderclouds into the stratosphere. They are thought to initiate in an electric breakdown between the positively charged upper region of a cloud and a layer of negative charge at the cloud boundary and in the air above. The breakdown forms a leader that transitions into streamers when propagating upwards. An international team of researchers (Denmark, Norway, Spain) report that they observed five intense, approximately 10-microsecond blue flashes from a thunderstorm cell. One flash initiated a pulsating blue jet […]
A New Institutional Approach to Research Security in the United States
Georgetown University January 2021 Most U.S. research and development (R&D) takes place in the private sector. To truly protect U.S. R&D, the government needs to empower frontline researchers as true partners. That means investing more in supporting security-informed decision making in business, philanthropy, and academia, and relying less on mandates and punitive tactics. To achieve these results, in a report “A New Institutional Approach to Research Security in the United States” researchers at Georgetown University propose a new, public-private research security clearinghouse, with leadership from academia, business, philanthropy, and government have a presence in the most active R&D hubs across […]
New metamaterial offers reprogrammable properties
Science Daily January 22, 2021 Researchers in Switzerland have developed metamaterial made of silicon and magnetic powder which has a complicated structure that allows mechanical properties to vary. Each cell within the structure behaves like an electrical switch. It is possible to activate and deactivate individual cells by applying a magnetic field which modifies the internal state of the metamaterial, and consequently its mechanical properties. The programmable material is analogous to computer devices like hard drives. The devices contain bits of data that can be written to and read from in real time. The cells in this programmable metamaterial, called […]
Storing information with light
Phys.org January 20, 2021 In the quest for energy efficient and fast memory elements, optically controlled ferroelectric memories are promising candidates. By taking advantage of the imprint electric field existing in the nanometric BaTiO3 films and their photovoltaic response at visible light, researchers in Spain have shown that the polarization of suitably written domains can be reversed under illumination. They used this effect to trigger and measure the associate change of resistance in tunnel devices. They showed that engineering the device structure by inserting an auxiliary dielectric layer, the electroresistance increases by a factor near 2 × 103%, and a robust electric […]
Using drones to create local quantum networks
Phys.org January 18, 2021 Researchers in China built a small laser-generating device and affixed it to one of the drones. As it fired, photons were split in two, creating entangled pairs. One of the paired photons was directed toward another drone while the other was directed to a ground station. The drone that received the entangled photon served only as a relay—after refocusing, the photon was forwarded to a third drone, which then sent it to a second ground station. Motorized devices were used on the drones to ensure transmitters and received lined up properly for transmission of the entangled […]
Using graphene, researchers increase optical data transmission speed by a factor of at least 10,000.
Nanowerk January 19, 2021 Conventional optical-fiber-based pulsed lasers have limits to increasing the number of pulses per second above the MHz level. Researchers in South Korea inserted an additional resonator containing graphene into a fiber-optic pulsed-laser oscillator that operates in the domain of femtoseconds (10-15 seconds). This increased data transmission and processing speeds significantly. They synthesized graphene, which has the characteristics of absorbing and eliminating weak light and amplifying the intensity by passing only strong light into the resonator. This allows the laser intensity change to be accurately controlled at a high rate, and thus the repetition rate of pulses […]