Science Daily March 22, 2022 An international team of researchers (Switzerland, France) has stored a qubit for 20 milliseconds in crystals doped with europium capable of absorbing light and then re-emitting it. They managed to reach the 100-millisecond mark with a small loss of fidelity. The crystals were kept at -273,15°C, because beyond 10°C above this temperature, the thermal agitation of the crystal destroys the entanglement of the atoms. In theory, it would be enough to increase the duration of exposure of the crystal to radio frequencies, but for the time being, technical obstacles to their implementation over a longer […]
Researchers develop silicon cuboid nanoantenna
Phys.org March 21, 2022 The Purcell effect is commonly used to increase the spontaneous emission rate by modifying the local environment of a light emitter. Researchers in China studied the scattering cross section, polarization charge distribution, and electromagnetic field distribution for electromagnetic plane wave illuminating the silicon dielectric cuboid nanoantenna and identified simultaneous existence of electric dipole (ED), magnetic dipole (MD) and electric quadrupole (EQ) emission resonance modes in this nanoantenna. When they calculated the Purcell factor of ED, MD, and EQ emitters with different moment orientations as a function of radiation wavelength by placing these point radiation source within […]
Researchers develop the world’s first power-free frequency tuner using nanomaterials
Science Daily March 18, 2022 Phase-change materials (PCMs) can switch between amorphous and crystalline states permanently yet reversibly. However, the change in their mechanical properties has largely gone unexploited. The most practical configuration using suspended thin-films suffer from filamentation and melt-quenching. An international team of researchers (UK, USA – University of Pennsylvania) used nanowires as active nanoelectromechanical systems (NEMS) to overcome these limitations. They achieved active modulation of the Young’s modulus in GeTe nanowires by exploiting a unique dislocation-based route for amorphization. The nanowire NEMS enable power-free tuning of the resonance frequency over a range of 30% and their high […]
Single-photon source paves the way for practical quantum encryption
Phys.org March 23, 2022 Researchers in Australia have developed an on-demand way to generate photons with high purity in a scalable and portable system that operates at room temperature. They combined hexagonal boron nitride with a hemispherical solid immersion lens, which increases the source’s efficiency by a factor of six. They incorporated the single-photon source into a fully portable device that can perform QKD. They demonstrated that it could produce over ten million single photons per second at room temperature. The streamlined device is easier to use and much smaller than traditional optical table setups allowing the system to be […]
Ultra-compact integrated photonic device could lead to new optical technologies
Phys.org March 17, 2022 In photonic circuits optical isolators are used to prevent light from reentering the system and destabilizing it. But guiding light in one direction often requires large magnets, making these circuits difficult to create on a small scale. By coupling light confined in a nanophotonic waveguide with an atomically thin, two-dimensional semiconductor, a team of researchers in the US (University of Chicago, Argonne National Laboratory) exploited the properties of both the light and the material to guide photons in one direction. They fabricated titanium dioxide waveguides directly on the surface of low-disorder, boron nitride-encapsulated tungsten diselenide (WSe2). […]
Warming oceans will significantly alter how sound travels underwater
Phys.org March 24, 2022 A considerable fraction of marine life depends on sound, marine mammals exploit sound in all aspects of their life. Researchers in Italy studied the impact of climate change in sound propagation by computing the three-dimensional global field of underwater sound speed based on present conditions (2006–2016) and a future climate scenario identifying two “acoustic hotspots” where larger sound speed variations are expected. Their results indicated that the identified acoustic hotspots would present substantial climate-change-induced sound speed variations toward the end of the century, potentially affecting the vital activities of species in the areas. They provided evidence […]
Top 10 Science and Technology Inventions for the Week of March 18, 2022
01. Hoverfly brains mapped to detect the sound of distant drones 02. Blowin’ in the wind – tiny battery-free sensor devices float like dandelion seeds (w/video) 03. Extracting mechanical work from superfast-expanding hydrogels 04. High-Energy Interactions Between Light and Matter Described by Advanced New Mathematical Model 05. Magnetism helps electrons vanish in high-temp superconductors 06. Quantum information: Light from rare-earth molecules 07. Researchers Set Record by Preserving Quantum States in Silicon Carbide for More Than Five Seconds 08. Revealing thermal runaway routes in lithium-sulfur batteries 09. ‘Self-driving’ lab speeds up research, synthesis of energy materials 10. Simpler graphene method paves […]
Are conferences worth time and money?
Phys.org March 14, 2022 A team researchers in the US (Northwestern University, industry) developed a new mathematical model to understand and predict how scientists form collaborations at both in-person and virtual conferences. They validated the model with extensive data. The results suggest that the way organizers design conferences can have a direct effect on which scientific collaborations are formed and, by extension, on the direction of scientific inquiry. The patterns of interaction during conferences can be used to predict who will subsequently form a new collaboration, even when interaction is prescribed rather than freely chosen. After applying its mathematical model […]
Blowin’ in the wind – tiny battery-free sensor devices float like dandelion seeds (w/video)
Nanowerk March 16, 2022 Inspired by plants which disperse their seeds using the wind researchers at the University of Washington developed and demonstrated wind dispersal of battery-free wireless sensing devices. The millimetre-scale devices weigh 30 milligrams and were designed on a flexible substrate using programmable, off-the-shelf parts to enable scalability and flexibility for various sensing and computing applications. The system is powered using lightweight solar cells and an energy harvesting circuit that is robust to low and variable light conditions and has a backscatter communication link that enables data transmission. To achieve the wide-area dispersal and upright landing they developed thin-film […]
California’s first lab-grown mosquitoes may take flight—stirring controversy
Phys.org March 15, 2022 A biotech firm is seeking permission to release 2 million genetically modified male mosquitoes, with a “kill switch” built into their DNA, into the open air of California. When they mate with wild insects, their offspring die, causing an eventual collapse of the population. They are targeting swarms of the mosquito, first detected in Los Angeles County in 2011, which have since spread northward into 20 California counties. Unlike California’s native mosquitoes which emerge at dusk, these black-and-white-striped invaders hunt for blood during the day, when people are outside. They transmit potentially fatal Zika, dengue, yellow […]