Phys.org August 28, 2024 Observations of heated O+ ions in the magnetosphere are consistent with resonant wave–particle interactions. By contrast, observations of cold supersonic H+ flowing out of the polar wind suggest the presence of an electrostatic field. An international team of researchers (USA – NASA Goddard Space Flight Center, Catholic University of America, Embry-Riddle Aeronautical University, University of New Hampshire, University of Colorado at Boulder, UC Berkeley, Penn State University, NASA Wallops Flight Facility, UK, Norway, Sweden, Svalbard and Jan Mayen) described the existence of an electric potential drop between 250 km and 768 km from a planetary electrostatic field generated […]
Study: Transparency is often lacking in datasets used to train large language models
MIT News August 30, 2024 To improve data transparency and understanding of training language models on vast, diverse and inconsistently documented datasets an international team of researchers (USA – MIT, Harvard, UC Irvine, industry, University of Colorado, Olin College of Engineering, Carnegie Mellon University, and France, Canada) convened a multi-disciplinary effort between legal and machine learning experts to systematically audit and trace more than 1,800 text datasets. They developed tools and standards to trace the lineage of these datasets, including their source, creators, licenses and subsequent use. They found sharp divides in the composition and focus of data licensed for […]
Top 10 Science and Technology Inventions for the Week of August 30, 2024
01. Nontoxic ceramic could replace lead-based electronic components 02. Toward a code-breaking quantum computer 03. Manipulation of nanolight provides new insight for quantum computing and thermal management 04. Materials scientists develop road map for designing responsive gels with unusual properties 05. World’s first micromachine twists 2D materials at will 06. Physicists ease path to entanglement for quantum sensing 07. Reconfigurable sensor can detect particles 0.001 times the wavelength of light 08. Proof-of-concept study demonstrates mid-infrared computational temporal ghost imaging 09. Study proposes generalized approach to light-matter interactions 10. Study of disordered rock salts leads to battery breakthrough And others DARPA […]
DARPA Launches Regional Commercial Accelerators
DARPA News August 22, 2024 DARPA has selected five top technology accelerators from across the nation as DARPA Commercial Accelerators to facilitate rapid commercialization and scale of DARPA-funded technologies. They include – Capital Factory, based in Austin, Texas, CIMIT, based out of Massachusetts General Hospital in Boston, FedTech (Hyperion Technologies LLC)Arlington, Virginia, SRI International, in Menlo Park, California, Wireless Research Center of North Carolina, based in Wake Forest, North Carolina. Accelerators will work with qualified DARPA-funded companies developing early-stage technologies, Access regional top-tier commercial and entrepreneurial talent and investor networks, Connect DARPA performers with private investment capital and U.S. corporations, […]
Manipulation of nanolight provides new insight for quantum computing and thermal management
Phys.org August 26, 2024 Anisotropic planar polaritons – hybrid electromagnetic modes mediated by phonons, plasmons, or excitons – in biaxial two-dimensional (2D) van der Waals crystals have attracted significant attention due to their fundamental physics and potential nanophotonic applications. An international team of researchers (USA – University of Minnesota, Auburn University, Purdue University, City University of New York, IBM T. J. Watson Research Center, Vanderbilt University, Republic of Korea, Spain) reviewed the properties of planar hyperbolic polaritons and methods that could be used to experimentally tune them. They argued that such natural, planar hyperbolic media should be common in biaxial […]
Materials scientists develop road map for designing responsive gels with unusual properties
Phys.org August 22, 2024 Metallo-polyelectrolytes are versatile materials for applications like filtration, biomedical devices, and sensors, due to their metal-organic synergy. Their dynamic and reversible electrostatic interactions offer high ionic conductivity, self-healing, and tunable mechanical properties. However, the knowledge gap between molecular-level dynamic bonds and continuum-level material properties persist, largely due to limited fabrication methods and a lack of theoretical design frameworks. To address this gap researchers at Caltech developed a framework, combining theoretical and experimental insights, highlighting the interplay of molecular parameters in governing material properties. Using stereolithography-based additive manufacturing, they produced durable metallo-polyelectrolytes gels with tunable mechanical properties […]
New research suggests a way to capture physicists’ most wanted particle—gravitons
Phys.org August 27, 2024 The quantization of gravity is widely believed to result in gravitons – particles of discrete energy that form gravitational waves. But their detection has so far been considered impossible. An international team of researchers (Sweden, Japan, USA – Stevens Institute of Technology) showed that signatures of single graviton exchange could be observed in laboratory experiments. They showed that stimulated and spontaneous single-graviton processes could become relevant for massive quantum acoustic resonators and that stimulated absorption could be resolved through continuous sensing of quantum jumps. They analyzed the feasibility of observing the exchange of single energy quanta […]
Nontoxic ceramic could replace lead-based electronic components
Phys.org August 24, 2024 Electrostrictors, materials developing mechanical strain proportional to the square of the applied electric field, present many advantages for mechanical actuation as they convert electrical energy into mechanical, but not vice versa. Both high relative permittivity and reliance on Pb as the key component in commercial electrostrictors pose serious practical and health problems. An international team of researchers (Israel, USA – Brown University, Stony Brook University) showed that ZrxCe1-xO2 has low relative permittivity, and electromechanical properties as electrostrictors – longitudinal electrostriction strain coefficient, and relaxation frequency. They showed that the elastic dipoles in ZrxCe1-xO2 are formed only […]
Physicists ease path to entanglement for quantum sensing
Phys.org August 26, 2024 Spin squeezing is a form of entanglement that reshapes the quantum projection noise to improve measurement precision. An international team of researchers (USA – Harvard University, UC Berkeley, Germany) provided numerical and analytic evidence for the following conjecture: any Hamiltonian exhibiting finite-temperature easy-plane ferromagnetism could be used to generate scalable spin squeezing, thereby enabling quantum-enhanced sensing. It is based on a connection between the quantum Fisher information of pure states and the spontaneous breaking of a continuous symmetry. They demonstrated that spin squeezing exhibits a phase diagram with a sharp transition between scalable squeezing and non-squeezing […]
Physicists predict existence of new exciton type
Phys.org August 27, 2024 Due to their bosonic nature, excitons are expected to condense and exhibit superfluidity at sufficiently low temperatures. In interacting Chern insulators, excitons may inherit the nontrivial topology and quantum geometry from the underlying electron wavefunctions. A team of researchers in the US (University of Oklahoma, City University of New York, Harvard University) theoretically investigated the excitonic bound states and superfluidity in flat-band insulators pumped with light. They found that the exciton wavefunctions exhibited vortex structures in momentum space, with the total vorticity being equal to the difference of Chern numbers between the conduction and valence bands. […]