Phys.org August 4, 2021 The use of graphene in a form of discontinuous flakes in polymer composites limits the full exploitation of the unique properties of graphene, thus requiring high filler loadings for achieving satisfactory electrical and mechanical properties. An international team of researchers (Greece, Italy) produced centimetre-scale CVD graphene/polymer nanolaminates by using an iterative ‘lift-off/float-on’ process. These have outperformed, for the same graphene content, state-of-the-art flake-based graphene polymer composites in terms of mechanical reinforcement and electrical properties. The thin laminate materials have shown a high electromagnetic interference (EMI) shielding effectiveness, reaching 60 dB for a small thickness of 33 μm, […]
Engineers bend light to enhance wavelength conversion
Nanowerk July 30, 2021 Incoming light can hit the electrons in the semiconductor lattice and move them to a higher energy state creating an electric field which further accelerates the high-energy electrons. They unload the extra energy by radiating it at different optical wavelengths, thus converting the wavelengths. An international team of researchers (USA – UCLA, Iowa State University, Germany) devised a solution for improving wavelength conversion using the semiconductor surface state phenomenon. They incorporated a nanoantenna array that bends incoming light, so it is confined around the shallow surface of the semiconductor converting the wavelength easily and without any […]
Exotic property of ‘ambidextrous’ crystals points to new magnetic phenomena
Phys.org August 4, 2021 Researchers in Sweden used symmetry-based analysis and numerical computations to predict the existence of antichiral ferromagnetism—a kind of ferromagnetic ordering when both types of chirality (handedness) exist simultaneously and alternate in space. They predicted a fundamentally different magnetic ordering in tetrahedral ferromagnets. They showed that antichiral ferromagnetism can be observed in a class of crystals in which many minerals are formed naturally by studying magnetic ordering in the structure with tetrahedral crystal symmetry and used micromagnetic analysis to derive the new antichiral ordering. The proposed magnetic ordering might result in a rich family of magnetic phenomena […]
Here’s What Ancient Climate Tipping Points May Be Able to Reveal About Earth’s Future
Science Alert July 30, 2021 In many cases, abrupt changes arise from slow changes in one component of the Earth system that eventually pass a critical threshold after which impacts cascade through coupled climate–ecological–social systems. The geological record provides the only long-term information we have on the conditions and processes that can drive physical, ecological, and social systems into new states or organizational structures that may be irreversible within human time frames. An international team of researchers (Germany, USA – Oregon State University, University Wisconsin, Arizona State University Tempe, UMass Amherst, Columbia University, USGS, University of Colorado, Northern Arizona University, […]
Major Atlantic Ocean current system might be approaching critical threshold
Science Daily August 5, 2021 The Atlantic Meridional Overturning Circulation, or AMOC, transports warm water masses from the tropics northward at the ocean surface and cold water southward at the ocean bottom. It influences weather systems worldwide. A potential collapse of this ocean current system could have severe consequences. An international team of researchers (Germany, UK) have developed a robust and general early-warning indicator for forthcoming critical transitions. Significant early-warning signals are found in eight independent AMOC indices, based on observational sea-surface temperature and salinity data from across the Atlantic Ocean basin. The findings support the assessment that the AMOC […]
A major challenge to harvesting fusion energy on Earth
Phys.org August 5, 2021 A key challenge to producing the fusion energy is preventing the runaway electrons that can bore holes in tokamaks. To see the electrons so that they can find ways to stop them before their population can grow into an avalanche an international team of researchers (USA – Princeton University, University of Wisconsin, Edgewood College, Japan, Switzerland) used a multi-energy pinhole camera which has the unique ability to record not only the properties of the plasma in time and space but its energy distribution as well. Use of the novel camera moves technology forward. Comparing their diagnosis […]
Nearly 14,000 Scientists Warn That Earth’s ‘Vital Signs’ Are Rapidly Worsening
Science Alert August 2, 2021 An international team of researchers (USA – Oregon State University, Tufts University, Australia, South Africa) suggests a “three-pronged near-term policy approach”: a significantly higher global price on carbon, a worldwide phase-out and eventual ban of fossil fuels, and development of climate reserves to protect and restore biodiversity and carbon sinks. They have presented a suite of graphical vital signs of climate change over the last 40 years for human activities that can affect GHG emissions and change the climate and climatic impacts using only relevant data sets that are clear, understandable, systematically collected for at […]
New approach to information transfer reaches quantum speed limit
Phys.org August 5, 2021 A team of researchers in the US (University of Maryland, University of Colorado) designed a quantum protocol that reaches the theoretical speed limits for certain quantum tasks. In the new protocol, data stored on one qubit is shared with its neighbors using entanglement. The qubits work together to spread it to other sets of qubits. Because more qubits are involved, they transfer the information even more quickly. This process can be repeated to generate larger blocks of qubits that pass the information faster and faster. They found that the snowballing qubits speed along the information at […]
Running quantum software on a classical computer
EurekAlert August 3, 2021 A key open question in quantum computing is whether quantum algorithms can potentially offer a significant advantage over classical algorithms for tasks of practical interest. An international team of researchers (USA – Flatiron Institute, Columbia University, Switzerland) has introduced a method to simulate layered quantum circuits consisting of parametrized gates suitable for near-term quantum computers. They used a neural-network parametrization of the many-qubit wavefunction focusing on states relevant for the Quantum Approximate Optimization Algorithm (QAOA). For the largest circuits simulated, they reached 54 qubits at 4 QAOA layers without requiring large-scale computational resources. For larger systems, […]
Towards next-gen computers: Mimicking brain functions with graphene-diamond junctions
Science Daily August 4, 2021 Researchers in Japan designed graphene-diamond junctions that can mimic the characteristics of biological synapses and key memory functions, opening the doors for next-generation image sensing memory devices. They demonstrated optoelectronically controlled synaptic functions using junctions between vertically aligned graphene (VG) and diamond. The fabricated junctions mimic biological synaptic functions when stimulated with optical pulses and exhibit other basic brain functions such as the transition from short-term memory (STM) to long-term memory (LTM). The VG-diamond arrays underwent redox reactions induced by fluorescent light and blue LEDs under a bias voltage. The researchers attributed this to the […]