01. New metasurface innovation unlocks precision control in wireless signals 02. Scientists find novel one-dimensional superconductor 03. Smart fabrics that cancel noise and sculpt sound 04. Compact quantum light processing: New findings lead to advances in optical quantum computing 05. A hydrocarbon molecule as supplier and energy storage solution for solar energy 06. New understanding of energy losses in emerging light source 07. A flexible and efficient DC power converter for sustainable-energy microgrids 08. How light can vaporize water without the need for heat 09. Researchers uncover kinky metal alloy that won’t crack at extreme temperatures at the atomic level […]
Compact quantum light processing: New findings lead to advances in optical quantum computing
Phys.org April 19, 2024 The polarization of single photons are used as addressable degrees of freedom for turning the interference of nonclassical states of light into practical applications. However, the scale-up for the processing of a large number of photons of these architectures is very resource-demanding due to the rapidly increasing number of components, such as optical elements, photon sources, and detectors. An international team of researchers (Austria, Italy, Belgium) demonstrated a resource-efficient architecture for multiphoton processing based on time-bin encoding in a single spatial mode. They used an efficient quantum dot single-photon source and a fast programmable time-bin interferometer […]
A flexible and efficient DC power converter for sustainable-energy microgrids
Science Daily April 19, 2024 An internal team of researchers (Japan, Taiwan) proposed a floating four-phase interleaved chargepump bidirectional dc-dc converter (F4P-ICPBDC) with wide Buck/Boost voltage ratio. The interleaved structure was used to mitigate the current ripple across the low-voltage side capacitor and inductors, while the floating configuration facilitated the high Buck/Boost voltage conversion ratio. To ensure a balanced average inductor current throughout the entire range of duty cycle, an asymmetric duty limit control strategy was implemented. Bidirectional synchronous rectification operations were seamlessly carried out without the need for additional hardware, which enhanced the overall converter efficiency. They developed a […]
How light can vaporize water without the need for heat
MIT News April 23, 2024 Although water is almost transparent to visible light, researchers at MIT demonstrated that the air–water interface interacts strongly with visible light via what they hypothesized as the photomolecular effect. In this effect, transverse-magnetic polarized photons cleave off water clusters from the air–water interface. They used 14 different experiments to demonstrate the existence of this effect and its dependence on the wavelength, incident angle, and polarization of visible light. They also demonstrated that visible light heats up thin fogs, suggesting that this process could impact weather, climate, and the earth’s water cycle and that it provided […]
A hydrocarbon molecule as supplier and energy storage solution for solar energy
Phys.org April 19, 2024 The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store and release a substantial amount of chemical energy. Prior work observed signatures of ultrafast molecular dynamics in both isomers upon ultraviolet excitation but could not follow the electronic relaxation all the way back to the ground state experimentally. An international team of researchers (USA – Kansas State University, University of Nebraska–Lincoln, SLAC National Accelerator Laboratory, Brown University, UK, Germany, Italy, Sweden, Australia) identified two competing pathways by which electronically excited quadricyclane molecules relaxed to the electronic ground state. The fast pathway (<100 femtoseconds) was […]
Light stands still in a deformed crystal
Phys.org April 24, 2024 Although in electronic crystals, magnetic fields can be used to induce a multitude of unique phenomena, the uncharged nature of photons necessitates alternative approaches to bring about similar control over photons at the nanoscale. Researchers in the Netherlands demonstrated experimentally pseudomagnetic fields in two-dimensional photonic crystals through engineered strain of the lattice. Taking advantage of the photonic crystal’s design freedom, they realized domains of opposite pseudomagnetic field and observed chiral edge states at their interface. They revealed that the strain-induced states could achieve remarkably high quality factors despite being phase matched to the radiation continuum. Together […]
Mess is best: Disordered structure of battery-like devices improves performance
Science Daily April 18, 2024 The difficulty in characterizing the complex structures of nanoporous carbon electrodes has led to a lack of clear design principles with which to improve supercapacitors. Charge is stored within the porous carbon structure, and pore size has thus long been viewed as the key factor for determining storage capacity. An international team of researchers (UK, France) evaluated commercial nanoporous carbons and did not find a correlation between pore size and capacitance. Rather, their combination of simulations and data measurements indicated that the key factor was the extent of disorder, as smaller graphene-like domains could more […]
A new chapter in quantum vortices: Customizing electron vortex beams
Nanowerk April 23, 2024 Almost all the experimentally created electron vortex beam (EVBs) manifest isotropic doughnut intensity patterns. Based on the correlation between local divergence angle of electron beam and phase gradient along azimuthal direction, researchers in China showed that free electrons could be tailored to EVBs with customizable intensity patterns independent of the carried OAM. As proof-of-concept, by using computer generated hologram and designing phase masks to shape the incident free electrons they tailored three structured EVBs carrying identical OAM to exhibit completely different intensity patterns. Through the modal decomposition, they quantitatively investigated their OAM spectral distributions and revealed […]
New metasurface innovation unlocks precision control in wireless signals
Nanowerk April 22, 2023 Polarization conversion and beam scanning metasurfaces are commonly used to reduce polarization mismatch and direct electromagnetic waves in a specific direction to improve the strength of a wireless signal. However, identifying suitable active and mechanically reconfigurable metasurfaces for polarization conversion and beam scanning is a considerable challenge, and the reported metasurfaces have narrow scanning ranges, are expensive, and cannot be independently controlled. Researchers in South Korea proposed a reconfigurable transmissive metasurface combined with a scissor and rotation actuator for independently controlling beam scanning and polarization conversion functions. They constructed metasurface with rotatable unit cells (UCs) that […]
New understanding of energy losses in emerging light source
Nanowerk April 18, 2024 Emerging light-emitting electrochemical cells (LECs) can be cost- and energy-efficiently fabricated by ambient-air printing by virtue of the in situ formation of a p-n junction doping structure. However, the in situ doping transformation renders a meaningful efficiency analysis challenging. Researchers in Sweden have developed a method for separation and quantification of major LEC loss factors, notably the outcoupling efficiency and exciton quenching. They found the shift in the position of the emissive p-n junction in common singlet-exciton emitting LECs to shift markedly with increasing current, and the influence of this shift on the outcoupling efficiency was […]