Phys.org July 8, 2024 Optical tweezers enable noncontact trapping of microscale objects using light. However, it is not known how tightly it is possible to three-dimensionally (3D) trap microparticles with a given photon budget. Reaching the limit would enable maximally stiff particle trapping for precision measurements on the nanoscale and photon-efficient tweezing of light-sensitive objects. An international team of researchers (UK, Austria) customized the shape of light fields to suit specific particles, with the aim of optimizing trapping stiffness in 3D. They showed, theoretically, that the confinement volume of microspheres held in sculpted optical traps could be reduced by one […]
Scientists find new way global air churn makes particles
Phys.org July 12, 2024 New particle formation in the free troposphere is a major source of cloud condensation nuclei globally. The prevailing view is that in the free troposphere, new particles are formed predominantly in convective cloud outflows. An international team of researchers (USA -Washington University, NASA Langley Research Center (VA), University of Colorado, NOAA (Boulder), National Center for Atmospheric Research, Boulder, Washington University in St. Louis, Austria) presented another mechanism using global observations. They found that during stratospheric air intrusion events, the mixing of descending ozone-rich stratospheric air with more moist free tropospheric background resulted in elevated hydroxyl radical […]
Small steps for electrons—big steps for the future? Ultrafast microscope reveals electron pathways in solar cells
Phys.org July 17, 2024 To understand the transport of photoexcited charge carriers for designing next-generation light-harvesting devices an international team of researchers (Germany, UK) simultaneously probed the intrinsic out-of-plane charge-carrier diffusion and the nanoscale morphology of the organic–inorganic metal halide perovskite FA0.83Cs0.17Pb(I1−xClx)3 by pushing depth-sensitive terahertz near-field nanospectroscopy to extreme subcycle timescales. By analysing deep-subcycle time shifts of the scattered terahertz waveform after photoexcitation, they accessed the vertical charge-carrier dynamics within single grains. At all the measured locations, despite topographic irregularities, diffusion was homogeneous on the 100 nm scale, although it varied between mesoscopic regions. According to the researchers linking in […]
What do research organizations think about open access publishing?
Phys.org July 8, 2024 Research Consulting and the Centre for Science and Technology Studies (CWTS) was commissioned to determine to what extent the vision, mission and objectives set out in the towards responsible publishing (TRP) proposal serve the needs of the global research community. Through a consultative approach, researchers in the UK sought to assess whether there is appetite for the type of change proposed by cOAlition S (an international consortium of research funding and performing organization’s) in the TRP proposal. In addition, they aimed to understand how the ‘Towards Responsible Publishing’ proposal may be modified or refined to ensure […]
Top 10 Science and Technology Inventions for the Week of July 12, 2024
01. A management strategy for producing scientific breakthroughs 02. Can a computer chip have zero energy loss in 1.58 dimensions? 03. Common plastics could passively cool and heat buildings with the seasons 04. Genetic algorithm enables precise design of phononic crystals 05. High-selectivity graphene membranes enhance CO₂ capture efficiency 06. New possibilities for reservoir computing with topological magnetic and ferroelectric systems 07. Novel 2D device for quantum cooling converts heat to voltage at ultra-low temperatures 08. Researchers develop technology to mass produce quantum dot lasers for optical communications 09. Scientists achieve first intercity quantum key distribution with deterministic single-photon source […]
Can a computer chip have zero energy loss in 1.58 dimensions?
Phys.org July 1, 2024 Topological insulators are known to exist in one (wire), two (sheet) and three (cube) dimensions; all with different possible applications in electronic devices. An international team of researchers (the Netherlands, China, Sweden) discovered that topological insulators may also exist at 1.58 dimensions, and that these could be used for energy-efficient information processing. They demonstrated that topological edge and corner modes arise in fractals formed upon depositing thin layers of bismuth on an indium antimonide substrate. Their scanning tunnelling microscopy results and theoretical calculations revealed the appearance and stability of nearly zero-energy modes at the corners of […]
China Will Have 1 Trillion Watts of Solar by the end of 2025
Next Big Future July 3, 2024 The National Energy Administration (NEA) reports China added 217GW of solar power and 76GW of wind power in 2023 – to reach a total capacity of 1,050GW. They need 15 Tesla Megapack factories (150,000 per year) worth of fixed storage every year for the additional wind and solar. This will increase as China accelerates solar and wind installation to meet AI data center demand. By May 2024, China had installed 690GW of solar capacity and 460GW of wind, which made up 38% of its power generation capacity. China is averaging about 1 MWh/year (2.8kWh/day) […]
A chip-scale titanium-sapphire laser
Nanowerk June 26, 2024 Ti:sapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of their large size, cost and need for high optical pump powers. An international team of researchers (USA – Stanford University, Belgium) demonstrated a monocrystalline titanium:sapphire-on-insulator (Ti:SaOI) photonics platform that enabled dramatic miniaturization, cost reduction and scalability of Ti:sapphire technology. Through the fabrication of low-loss whispering-gallery-mode resonators, they realized a Ti:sapphire laser operating with an ultralow, sub-milliwatt lasing threshold; through orders-of-magnitude improvement in mode confinement in Ti:SaOI waveguides, they realized an integrated solid-state optical amplifier operating below 1 μm. They amplified distortion-free […]
Controlling magnetism with polarized light: Non-thermal pathway uses inverse Faraday effect
Phys.org July 5, 2024 Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism on timescales as short as the excitation pulse itself. As the IFE scales with the spin-orbit coupling strength of the involved electronic states, photo-exciting the strongly spin-orbit coupled core-level electrons in magnetic materials appears as an appealing method to transiently generate large opto-magnetic moments. An international team of researchers (Germany, France, Canada, Italy, Spain, Slovenia, Sweden, UK) investigated this scenario in a ferrimagnetic GdFeCo alloy by using intense and circularly polarized […]
Common plastics could passively cool and heat buildings with the seasons
Science Daily June 27, 2024 Vertical facades of buildings mostly see terrestrial features that become broadband-radiative heat sources in the summer and heat sinks in the winter. The resulting summertime terrestrial heat gain by buildings overwhelms their narrowband longwave infrared (LWIR) radiative cooling to space, while the wintertime terrestrial heat loss causes overcooling. A team of researchers in the US (Princeton University, Oak Ridge National Laboratory, UCLA, Arizona State University) showed that selective LWIR emitters on vertical building facades could exploit the differential transmittance of the atmosphere toward the sky and between terrestrial objects to achieve higher summertime cooling and […]