EurekAlert June 7, 2021 Researchers at the Pennsylvania State University are exploring the requirements for electric vertical takeoff and landing (eVTOL) vehicles and designing and testing potential battery power sources. eVTOL’s unique operating profiles and requirements present grand challenges to batteries. The team’s work identifies the primary battery requirements for eVTOL in terms of specific energy and power, fast charging, cycle life, and safety, revealing that eVTOL batteries have more stringent requirements than electric vehicle batteries in all aspects. They found that fast charging is essential for downsizing aircraft and batteries for low cost while achieving high vehicle utilization rates […]
Lead halide perovskites – a horse of a different color
Nanowerk June 7, 2021 To capture the full range of the photophysical processes that occur in metal halide perovskites an international team of researchers (Sweden, Russia, Germany) has developed a novel spectroscopic technique for the study of charge carrier dynamics in lead halide perovskites. This methodology is based on the complete mapping of the photoluminescence quantum yield and decay dynamics in the 2D space of both fluence and frequency of the excitation light pulse. They offer a complete representation of the sample’s photo physics, allow examining the validity of theories by applying a single set of theoretical equations and parameters to […]
Novel materials: Sound waves traveling backwards
Nanowerk June 10, 2021 Acoustic waves in gases, liquids, and solids usually travel at an almost constant speed of sound. However, rotons, quasiparticles, are an exception: their speed of sound changes significantly with the wavelength, and it is also possible that the waves travel backwards. Rotons were predicted in 1962 in the context of superfluidity. Until now, they could only be observed under special quantum-physical conditions at very low temperatures – and were therefore not suitable to technical applications. An international team of researchers (Germany, France) propose an artificial material that can produce rotons without any quantum effects under normal […]
Online ‘library of properties’ helps to create safer nanomaterials
Nanowerk June 8, 2021 Under the European Union H2020-funded NanoSolveIT project an international team of researchers (Cyprus, UK) has developed a decision support system in the form of both stand-alone open software and a freely available cloud library containing full physicochemical characterisation of 69 nanomaterials, plus calculated molecular descriptors to increase the value of the available information. The dataset contains over 70 descriptors per nanomaterial. Over the last two years, this project has already presented some very impressive results with more than 30 publications, making NanoSolveIT one of the most active projects in the nanomaterials safety and informatics space. The […]
Quantum holds the key to secure conference calls
EurekAlert June 6, 2021 Traditional quantum communication protocols consume pair-wise entanglement, which is suboptimal for distributed tasks involving more than two users. An international team of researchers (UK, Germany) has demonstrated quantum conference key agreement leveraging multipartite entanglement to efficiently create identical keys between N users with up to N-1 rate advantage in constrained networks. They distributed four-photon Greenberger-Horne-Zeilinger (GHZ) states, generated by high-brightness telecom photon-pair sources over optical fiber with combined lengths of up to 50 km and performed multiuser error correction and privacy amplification. Under finite-key analysis, they established 1.5 × 106 bits of secure key, which were […]
A quantum step to a heat switch with no moving parts
Science Daily June 7, 2021 Based on foundational theory a team of researchers in the US (Iowa State University, University of Ohio, University of Chicago) engineered an alloy with the elements bismuth and antimony at precise ranges. In this material electrons move like massless photons, a phenomenon theoretically predicted to exist. Under the influence of an external magnetic field some of the electrons generate energy, while others absorb energy, effectively turning the material into an energy pump resulting in 300% increase in its thermal conductivity. The mechanism is turned off if the magnet is taken away. This property, and the […]
Researchers create intelligent electronic microsystems from ‘green’ material
Science Daily June 8, 2021 The signal mismatch between the environmental stimuli and driving amplitude in neuromorphic devices has limited the functional versatility and energy sustainability. Researchers at UMass Amherst have demonstrated multifunctional, self-sustained neuromorphic interfaces by achieving signal matching at the biological level. The advances rely on the unique properties of microbially produced protein nanowires, which enable both bio-amplitude (e.g., <100 mV) signal processing and energy harvesting from ambient humidity. Integrating protein nanowire-based sensors, energy devices and memristors of bio-amplitude functions yields flexible, self-powered neuromorphic interfaces that can intelligently interpret biologically relevant stimuli for smart responses. These features, coupled with […]
Researchers create quantum microscope that can see the impossible
Phys.org June 9, 2021 The performance of light microscopes is limited by the stochastic nature of light. Randomness in the times that photons are detected introduces shot noise, which fundamentally constrains sensitivity, resolution, and speed. Although the long-established solution to this problem is to increase the intensity of the illumination light, this is not always possible when investigating living systems, because bright lasers can severely disturb biological processes. An international team of researchers (Australia, Germany) has experimentally shown that quantum correlations allow a signal-to-noise ratio beyond the photodamage limit of conventional microscopy. They developed a coherent Raman microscope that offers […]
Researchers realize unconventional coherent control of solid-state spin qubits
Phys.org June 9,2021 Optically detected magnetic resonance (ODMR) technology offers a readout approach to detect the spin state. Conventional ODMR detection of solid-state spin states are almost all under Strokes excitation, which requires that the excitation laser has higher energy than emitted photons. An international team of researchers (China, Hungary) investigated the dependence of laser power and temperature on AS excited ODMR signals, the researchers proved that the AS photoluminescence (PL) was induced by phonon-assisted single photon absorption process and was applicable to all-optical high-temperature temperature sensing. Based on this, they found that AS and Strokes excited ODMR followed similar […]
Saving the climate with solar fuel
EurekAlert June 8, 2021 Synthetic methane is easy to substitute in the vehicle fleet as the existing infrastructure – grid, storage, filling stations and trade mechanisms allow a comparatively fast substitution of fossil natural gas by synthetic methane for light and heavy-duty vehicles. Researchers in Switzerland discussed the direct potential for substitution of parts of the newly registered vehicle fleet with gas vehicles, fueled with synthetic methane, and compared it to the potential of using fuel cell electric vehicles relying on hydrogen. They analyzed the production path of hydrogen and synthetic methane with respect to electricity demand and overall associated […]