Phys.org March 13, 2024 MeV temperature electrons generation at non-relativistic intensities with high repetition rate lasers is important for the realization of compact, ultra-fast electron sources. An international team of researchers (India, UK, China) developed a technique of dynamic target structuring of micro-droplets using a millijoule class laser that used two collinear laser pulses; the first to create a concave surface in the liquid drop and the second, to dynamically-drive electrostatic plasma waves that accelerated electrons to MeV energies. The acceleration mechanism, identified as two plasmon decay instability was shown to generate two beams of electrons with hot electron temperature […]
You don’t need glue to hold these materials together—just electricity
Phys.org March 13, 2024 Researchers at the University of Maryland discovered that hard, electrical conductors (e.g., metals or graphite) could be adhered to soft, aqueous materials (e.g., hydrogels, fruit, or animal tissue) by a low DC electric field. They applied 5 V DC to graphite slabs spanning a tall cylindrical gel of acrylamide which resulted in a strong adhesion between the anode (+) and the gel in about 3 min. This adhesion lasted after the field was removed. They called it hard–soft electroadhesion or EA[HS]. Depending on the material, adhesion occurred at the anode (+), cathode (−), or both electrodes. […]
Top 10 Science and Technology Inventions for the Week of March 8, 2024
01. Designing a drone that uses adaptive invisibility: Towards autonomous sea-land-air cloaks 02. New class of 2D material displays stable charge density wave at room temperature 03. Research team develops a wireless sensor for spotting chemical warfare agents 04. Researchers create new compound to build space-age antennas 05. Scientists launch hub to channel quantum power for good 06. Tests show high-temperature superconducting magnets are ready for fusion 07. Zero-index metamaterials and the future 08. Making quantum bits fly 09. Research team develops a more durable coating against ice 10. Researchers provide unprecedented view into aerosol formation in Earth’s lower atmosphere […]
Better neutron mirrors can reveal the inner secrets of matter
Science Daily February 29, 2024 The state-of-the-art multilayer polarizing neutron optics has limitations, particularly low specular reflectivity and polarization at higher scattering vectors/angles, and the requirement of high external magnetic fields to saturate the polarizer magnetization. An international team of researchers (Sweden, Iceland, Switzerland, Germany) showed that, by incorporating 11B4C into Fe/Si multilayers, amorphization and smooth interfaces could be achieved, yielding higher neutron reflectivity, less diffuse scattering, and higher polarization. Magnetic coercivity was eliminated, and magnetic saturation could be reached at low external fields. According to the researchers this approach offered prospects for substantial improvement in polarizing neutron optics with […]
Correlation spectroscopy research shows network of quantum sensors boosts precision
Phys.org March 4, 2024 The coherence time of the quantum system surpasses that of the oscillator probing the system. Correlation spectroscopy overcomes this limitation by probing two quantum systems with the same noisy oscillator for a measurement of their transition frequency difference enabling very precise comparisons of atomic clocks. An international team of researchers (Austria, Israel, USA – Caltech) extended correlation spectroscopy to the case of multiple quantum systems undergoing strong correlated dephasing. They modelled Ramsey correlation spectroscopy with N particles as a multiparameter phase estimation problem and demonstrated that multiparticle correlations could assist in reducing the measurement uncertainties even […]
Designing a drone that uses adaptive invisibility: Towards autonomous sea-land-air cloaks
Phys.org March 6, 2024 An omnidirectional flying cloak has not been achieved so far, primarily due to the challenges associated with dynamic synthesis of metasurface dispersion. Researchers in China have demonstrated an autonomous aero amphibious invisibility cloak that incorporated a suite of perception, decision, and execution modules, capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external stimuli… read more. Open Access TECHNICAL ARTICLE
Light stimulates a new twist for synthetic chemistry
Nanowerk February 28, 2024 Photoinduced concerted multiple-bond rotation has been proposed in some biological systems. However, the observation of such phenomena in synthetic systems has been a challenge in the photochemistry field. Researchers in Japan described a chalcogen-substituted benzamide system that exhibits photoinduced dual bond rotation in heteroatom-containing bonds. Introduction of the chalcogen substituent into a sterically hindered benzamide system provided sufficient kinetic stability and photosensitivity to enable the photoinduced concerted rotation. The presence of two different substituents on the phenyl ring in the thioamide derivative enabled the generation of a pair of enantiomers and E/Z isomers. Using these four […]
Making quantum bits fly
Nanowerk March 6, 2024 Matter qubit to traveling photonic qubit conversion is the cornerstone of numerous quantum technologies such as distributed quantum computing, as well as several quantum internet and networking protocols. Researchers in Germany formulated a theory for stimulated Raman emission which is applicable to a wide range of physical systems, including quantum dots, solid-state defects, and trapped ions, and various parameter regimes. They found the upper bound for the photonic pulse emission efficiency of arbitrary matter qubit states for imperfect emitters and showed a path forward to optimizing the fidelity. Based on these results, they proposed a paradigm […]
More than 2 million research papers have disappeared from the Internet
Nature March 4, 2024 A researcher at the University of London tested 7,438,037 works labelled with digital object identifiers (DOIs) and found that one-quarter of scholarly articles are not being properly archived and preserved indicating that systems to preserve papers online have failed to keep pace with the growth of research output. The sample was made up of a random selection of up to 1,000 registered to each member organization. Twenty-eight percent of these works — more than two million articles — did not appear in a major digital archive. Small publishers are at higher risk of failing to preserve […]
New class of 2D material displays stable charge density wave at room temperature
Phys.org March 1, 2024 Charge density waves are emergent quantum states that spontaneously reduce crystal symmetry, drive metal-insulator transitions, and precede superconductivity. In low-dimensions, distinct quantum states arise, however, thermal fluctuations and external disorder destroy long-range order. A team of researchers in the US (University of Michigan, Harvard University) has stabilized ordered 2D charge density waves through endotaxial synthesis of confined monolayers of 1T-TaS2. Specifically, an ordered incommensurate charge density wave (oIC-CDW) was realized in 2D with dramatically enhanced amplitude and resistivity. By enhancing CDW order, the hexatic nature of charge density waves became observable. Upon heating via in-situ TEM, […]