Phys.org July 25, 2024 The detection of faint magnetic fields from single-electron and nuclear spins at the atomic scale is a long-standing challenge in physics. While current mobile quantum sensors achieve single-electron spin sensitivity, atomic spatial resolution remains elusive for existing techniques. An international team of researchers (Germany, South Korea) fabricated a single-molecule quantum sensor at the apex of the metallic tip of a scanning tunnelling microscope by attaching Fe atoms and a PTCDA (3,4,9,10-perylenetetracarboxylic-dianhydride) molecule to the tip apex. They addressed the molecular spin by electron spin resonance and achieved ~100 neV resolution in energy. In a proof-of-principle experiment, they […]
New research underscores the close relationship between Saharan dust and hurricane rainfall
Phys.org July 24, 2024 The impact of global climate changes on Tropical Cyclone Rainfall (TCR) is complex and debatable. A team of researchers in the US (Western Michigan State University, Stanford University, Perdue University, University of Utah, Caltech) used an XGBoost machine learning model with 19-year meteorological data and hourly satellite precipitation observations to predict TCR for individual storms. The model identified dust optical depth (DOD) as a key predictor that enhances performance evidently. The model uncovered a nonlinear and boomerang-shape relationship between Saharan dust and TCR, with a TCR peak at 0.06 DOD and a sharp decrease thereafter. This […]
New study disputes Hunga Tonga volcano’s role in 2023–24 global warm-up
Phys.org July 26, 2024 The Hunga Tonga-Hunga Ha’apai (Hunga) submarine volcanic eruption on 15 January 2022 produced aerosol and water vapor plumes in the stratosphere. An international team of researchers (Canada, USA – industry, Texas A&M) calculated the climate forcing for the 2 years after the 15 January 2022, Hunga Tonga-Hunga Ha’apai (Hunga) eruption using satellite observations of stratospheric aerosols, trace gases and temperatures to compute the tropopause radiative flux changes relative to climatology. The net downward radiative flux decreased compared to climatology. The Hunga stratospheric water vapor anomaly initially increased the downward infrared radiative flux, but this forcing diminished […]
New transistor’s superlative properties could have broad electronics applications
MIT News July 26, 2024 Ferroelectric materials change polarization in response to an electric field and are useful for memory. However, these materials often suffer from fatigue as they are cycled many times, capping their lifetime. An international team of researchers (USA – MIT, Harvard, Japan) investigated the performance of a ferroelectric field-effect transistor (FeFET) based on sliding ferroelectricity in bilayer boron nitride at room temperature. Sliding ferroelectricity represents a different form of atomically thin 2D ferroelectrics, characterized by the switching of out-of-plane polarization through interlayer sliding motion. They examined the FeFET device employing monolayer graphene as the channel layer, […]
Optical fibers fit for the age of quantum computing
Phys.org July 29, 2024 Researchers in the UK summarized recent progress in the development and applications of microstructured optical fibers for quantum technologies. The optical nonlinearity of solid-core and gas-filled hollow-core fibers provides a valuable medium for the generation of quantum resource states as well as for quantum frequency conversion between the operating wavelengths of existing quantum photonic material architectures. The low loss, low latency, and low dispersion of hollow-core fibers make these fibers particularly attractive for both short- and long-distance links in quantum networks. Hollow-core fibers also promise to replace free-space optical components in a wide range of atomic […]
Raindrops grow with turbulence in clouds: New findings could improve weather and climate models
Phys.org July 25, 2024 A team of researchers in the US (NSF National Center for Atmospheric Research, industry) provided substantial evidence for significant impacts of turbulence on the evolution of cloud droplet size distributions and rain formation by comparing high-resolution observations of cumulus congestus clouds with state-of-the-art large-eddy simulations coupled with a Lagrangian particle-based microphysics scheme. Turbulence causes earlier rain formation and greater rain accumulation compared to simulations with gravitational coalescence only. The observed rain size distribution tail just above cloud base follows a power law scaling that deviates from theoretical scalings considering either a purely gravitation collision kernel or […]
Researchers trap atoms, force them to serve as photonic transistors
Phys.org July 29, 2024 It remains a challenging task to efficiently trap a large ensemble of cold atoms on an integrated nanophotonic circuit. Researchers at Purdue University demonstrated direct loading of an ensemble of up to 70 atoms into an optical microtrap on a nanophotonic microring circuit by employing degenerate Raman-sideband cooling in the microtrap, where a built-in spin-motion coupling arose directly from the vector light shift of the evanescent-field potential on a microring. Atoms were cooled into the trap via optical pumping with a single free space beam. They achieved a trap lifetime approaching 700 ms under continuous cooling. […]
Revealing the influences on La Niña and El Niño weather conditions
Phys.org July 31, 2024 Despite common background La Niña conditions, Australia was very dry in November 2020 and wet in November 2021. Researchers in Australia examined the El Niño Southern Oscillation, Indian Ocean Dipole, Southern Annular Mode and Madden Julian Oscillation, but they did not find obvious clues. They found that the absence (in 2020) or presence (in 2021) of an enhanced thermal wind and subtropical jet over the Australian continent contributed to the rainfall anomalies. In November 2021 the warm sea surface temperatures led to an enhanced meridional temperature gradient and subtropical jet over Australia. The enhanced jet provided […]
Scared to negotiate job offers? Study suggests you should do it anyway
Phys.org July 18, 2024 A team of researchers in the US (George Mason University, Stony Brook University, University of Pennsylvania) proposed that one major issue that individuals are concerned about in the context of job offers, is an offer being withdrawn from the bargaining table—losing out on a deal entirely. They investigated job candidates’ perceived likelihood of jeopardizing a deal, as compared to hiring managers’ reports, across seven studies, including surveys of academic job candidates and members of academic hiring committees, managers and hiring professionals, and experimental studies with interactive, incentivized negotiations conducted both in person and online. They found […]
Study: Gases from burning biomass react within clouds, forming secondary organic aerosols
Phys.org July 24, 2024 A team of researchers in the US (Pacific Northwest National Laboratory, UC Davis) developed a stand-alone box model to investigate four phenolic compounds, i.e., phenol, guaiacol, syringol, and guaiacyl acetone (GA), which represent some of the key potential sources of aqSOA from biomass burning in clouds. They predicted that the aqSOA formation potential (defined as aqSOA formed per unit dissolved organic gas concentration) of these phenols was higher than that of isoprene-epoxydiol (IEPOX), a well-known aqSOA precursor. Their simulations suggested that highly soluble and reactive multifunctional phenols like GA would predominantly undergo cloud chemistry within cloud […]