The so-called Casimir force or Casimir effect is a quantum mechanical phenomenon resulting from fluctuations in the electromagnetic field between two conducting or dielectric surfaces that are a short distance apart. Studies have shown that this force can be either be attractive or repulsive, depending on the dielectric and magnetic properties of the materials used in experiments.
Researchers at University of Tsukuba have developed an ultrafast time-resolved scanning electron microscopy instrument by integrating a scanning electron microscope with a femtosecond laser. This innovative system facilitates the observation of the instantaneous states of various materials. Their paper is published in the journal ACS Photonics.
UCLA researchers have created a new type of imager that can capture features much smaller than the limitations of traditional optical systems. This innovation has the potential to revolutionize fields like bioimaging, lithography and material science. The research is published in the journal eLight.
Researchers from Skoltech, Jilin University and Beijing HPSTAR in China, and their German colleagues have synthesized and studied a new type of hydrogen-rich superconductor. Technically referred to as an A15-type lanthanum superhydride, with the formula La4H23, it shows superconductivity below minus 168 degrees Celsius at a pressure of 1.2 million atmospheres. The research results were published in the National Science Review.
Polyhydrides are a novel class of compounds synthesized at about 1 million times the normal atmospheric pressure on Earth. They can exhibit unique superconducting properties with record-high critical temperatures of up to-23 C in lanthanum decahydride LaH10, critical magnetic fields reaching 300 tesla, and critical current densities.
Even compared to other similar hydrides, the newly discovered La4H23 behaves unusually: It has a negative temperature coefficient of electrical resistance in a certain pressure range. That is, unlike ordinary metals, with a decrease in temperature its electrical resistance does not decrease but grows, the way it happens in semiconductors and many unconventional superconductors, such as cuprates.
Inspired by the materials found in oyster and abalone shells, engineers at Princeton have developed a groundbreaking cement material.
The transition from traditional 2D to 3D microfluidic structures is a significant advancement in microfluidics, offering benefits in scientific and industrial applications. These 3D systems improve throughput through parallel operation, and soft elastomeric networks, when filled with conductive materials like liquid metal, allowing for the integration of microfluidics and electronics.
Astronomers at MIT, NASA, and elsewhere have a new way to measure how fast a black hole spins, by using the wobbly aftermath from its stellar feasting.
The method takes advantage of a black hole tidal disruption event—a blazingly bright moment when a black hole exerts tides on a passing star and rips it to shreds. As the star is disrupted by the black hole’s immense tidal forces, half of the star is blown away, while the other half is flung around the black hole, generating an intensely hot accretion disk of rotating stellar material.
The MIT-led team has shown that the wobble of the newly created accretion disk is key to working out the central black hole’s inherent spin.
So what else is faked material and what is structural integrity in the world of fakes?
“The planes that included components made with the material were built between 2019 and 2023, among them some Boeing 737 Max…”
Monolayer 2D semiconductors, such as WS2, exhibit uniquely strong light–matter interactions due to exciton resonances that enable atomically thin optical elements. Similar to geometry-dependent plasmon and Mie resonances, these intrinsic material resonances offer coherent and tunable light scattering. Thus far, the impact of the excitons’ temporal dynamics on the performance of such excitonic metasurfaces remains unexplored. Here, we show how the excitonic decay rates dictate the focusing efficiency of an atomically thin lens carved directly out of exfoliated monolayer WS2. By isolating the coherent exciton radiation from the incoherent background in the focus of the lens, we obtain a direct measure of the role of exciton radiation in wavefront shaping. Furthermore, we investigate the influence of exciton–phonon scattering by characterizing the focusing efficiency as a function of temperature, demonstrating an increased optical efficiency at cryogenic temperatures. Our results provide valuable insights into the role of excitonic light scattering in 2D nanophotonic devices.
As machine learning models are becoming mainstream tools for molecular and materials research, there is an urgent need to improve the nature, quality, and accessibility of atomistic data. In turn, there are opportunities for a new generation of generally applicable datasets and distillable models.