Science Daily December 7, 2022 A team of researchers in the US (Stanford University, SLAC National Accelerator Laboratory, UC Berkeley) found that anchored solvent molecules can increase the ionic conductivity of the electrolyte without undermining its non-flammability. They developed a liquid-state polymer electrolyte composed of LiFSI salts, dimethoxyethane (DME) solvents, and polysiloxane tethered with ion-solvating moieties. DME coordinated with both the salt and the polymer, while, together with the salt, they synergistically plasticized the polymer to increase the ionic conductivity. The resulting non-flammable polymer electrolyte had a room-temperature ionic conductivity of 1.6 mS/cm and a wide operation window of 25°C–100°C. […]
High-performance and compact vibration energy harvester created for self-charging wearable devices
Science Daily November 29, 2022 Vibration energy harvesters suffer from a significant drop in performance for non-steady-state vibrations, which are important for practical applications. Researchers in Japan demonstrated that the output power under an impulsive force can be increased significantly by placing a U-shaped metal component, called a dynamic magnifier (DM), under a MEMS piezoelectric vibration energy harvester (MEMS-pVEH) with a Pb(Zr,Ti)O3 film. Based on the results of numerical calculations they designed DM to have the same resonant frequency as the MEMS-pVEH and a high mechanical quality factor (). They measured the waveforms of the output voltage of the fabricated […]
Iron for energy storage
Max-Plank Society December 2, 2022 The combustion of iron powders seems very promising for stable and high-density energy storage technology. To better understand their in-process morphological and microstructural evolution an international team of researchers (Germany, the Netherlands) investigated two iron powder combustion pathways, one in air and one with the assistance of a propane pilot flame. Both processes resulted in spherical hollow particles composed of a complex microstructure of wüstite, magnetite and/or hematite. They observed nanoparticles on the micro-sized combustion products which indicated partial evaporation. According to the researchers the associated gas production inside the liquid droplet could be the […]
Milestone for laser technology
Science Daily December 5, 2022 To make free-electron lasers (FELs) smaller and more cost-effective, an international team of researchers (Israel, Japan, Germany, France, USA – UT Austin) has demonstrated seeded FEL lasing in the ultraviolet regime based on laser-plasma accelerator-driven free-electron laser in a seeded configuration, where control over the radiation wavelength was accomplished. The appearance of interference fringes, resulting from the interaction between the phase-locked emitted radiation and the seed, confirmed longitudinal coherence. Based on their work the researchers anticipate a navigable pathway to extreme-ultraviolet wavelengths, paving the way towards smaller-scale free-electron lasers, unique tools for a multitude of […]
New instrument measures supercurrent flow; data has applications in quantum computing
Phys.org December 5, 2022 To understand the inner workings of quantum computing and enable supercomputing a team of researchers in the US (Iowa State University, University of Alabama at Birmingham, University of Wisconsin-Madison, Madison, Florida State University, Ames National Laboratory) built a Cryogenic Magneto-Terahertz Scanning Near-field Optical Microscope (cm-SNOM). It comprises three main equipment: i) a 5 T split pair magnetic cryostat with a custom made insert for mounting SNOM inside; ii) an atomic force microscope (AFM) unit that accepts ultrafast THz excitation and iii) a MHz repetition rate, femtosecond laser amplifier for high-field THz pulse generation and sensitive detection. […]
On-demand storage of photonic qubits at telecom wavelengths
Phys.org December 6, 2022 Researchers in China processed a fiber-integrated quantum memory at telecom wavelengths based on a laser-written waveguide fabricated in an erbium-doped yttrium silicate. Both ends of the waveguide memory were directly connected with fiber arrays with a fiber-to-fiber efficiency of 51%. Storage fidelity of 98.3(1)% was obtained for time-bin qubits encoded with single-photon-level coherent pulses, which is far beyond the maximal fidelity that can be achieved with a classical measure and prepared strategy. This device featured high reliability and easy scalability, and it can be directly integrated into fiber networks, which could play an essential role in […]
Photonics – extending the spectrum
Nanowerk December 6, 2022 Despite remarkable manufacturing advantages, reliance on silicon-based waveguides currently limits the spectral window available to photonic integrated circuits (PICs). A team of researchers in the US (industry, UC Santa Barbara, Caltech) has developed a technique to enable photonic chips to operate in the visible-to-near-infrared spectrum by directly uniting III–V materials with silicon nitride waveguides on Si wafers. Using this technology, they fabricated a fully integrated PIC at photon energies greater than the bandgap of silicon, demonstrating essential photonic building blocks, including lasers, amplifiers, photodetectors, modulators, and passives, all operating at submicrometre wavelengths. Using this platform, they […]
Proposing a new idea for spacecraft propulsion that involves dynamic soaring
Phys.org December 6, 2022 Inspired by the dynamic soaring maneuvers performed by sea birds and gliders in which differences in wind speed are exploited to gain velocity, an international team of researchers (Canada, USA – industry) proposed a technique in which a lift-generating spacecraft circles between regions of the heliosphere that have different wind speeds, gaining energy in the process without the use of propellant and only modest onboard power requirements. Detailed models of the spacecraft trajectory were developed to predict the potential velocity gains and the maximum velocity that might be achieved in terms of the lift-to-drag ratio of […]
Quantum leap for research into unhackable communications networks
Phys.org November 30, 2022 Quantum steering relaxes the strict technological constraints of Bell nonlocality by reframing it in an asymmetric manner, with a trusted party only on one side. However, tests of quantum steering still require either extremely high-quality entanglement or very low loss. An international team of researchers (UK, Switzerland) constructed a test of quantum steering for qudits harnessing the advantages of high-dimensional entanglement to be simultaneously noise robust and loss tolerant. It was designed for single-detector measurements and was able to close the fair-sampling loophole in a time-efficient manner. They demonstrated quantum steering in up to 53 dimensions, […]
Researchers advance insights into cause of ripples on icicles
Science Daily December 5, 2022 Icicles that have grown from slightly impure water develop ripples around their circumference. The ripples have a near-universal wavelength and are thought to be the result of a morphological instability. Researchers in Canada used laboratory-grown icicles and various species of impurities, including fluorescent dye, to show that a certain fraction of the impurities remains trapped inside the icicle, forming inclusions within the ice. The inclusions were organized into chevron patterns aligned with the peaks of the ripples. Within the chevrons, there was a substructure of crescent-shaped structures. They also examined the crystal grain structure of […]