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Article  "Impossible" photonic breakthrough + Room-temperature superconductor meets resistence

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"Impossible" photonic breakthrough: scientists manipulate light at sub-wavelength scale
https://thedebrief.org/impossible-photon...gth-scale/

INTRO: In a potential breakthrough in the field of photonics, a team of researchers reports they have successfully manipulated light at the sub-wavelength scale.

Previously thought to be impossible, the movement of light at distances sizes smaller than its specific wavelength could lead to an entirely new field of microscopic material manipulation, with additional applications in the fields of DNA programming and nanoscale fabrication.

Researchers in a variety of fields employ a device known as optical tweezers. By using a pair of lasers focused down to their smallest sizes, optical tweezers allow for the manipulation of material and objects at extremely small scales. For example, researchers studying DNA are able to use optical tweezers to manipulate single proteins or other biological materials at sizes too small for mechanical tweezers to operate.

Still, even optical tweezers have their limits. Current designs used lenses to focus the twin lasers to the smallest point possible, but the actual size of the light wavelength has limited just how precise even this ultra-precision instrument can be. Now, researchers say they have broken that seemingly unbreakable limit, which may pave the way for a whole new range of microscopic optical applications... (MORE - details)

RELATED (eurekalert): Scientists push the boundaries of manipulating light at the submicroscopic level


Room-temperature superconductor discovery meets with resistance
https://www.quantamagazine.org/room-temp...e-20230308

INTRO: In a packed talk on Tuesday afternoon at the American Physical Society’s annual March meeting in Las Vegas, Ranga Dias, a physicist at the University of Rochester, announced that he and his team had achieved a century-old dream of the field: a superconductor that works at room temperature and near-room pressure. Interest was so intense in the presentation that security personnel stopped entry to the overflowing room more than fifteen minutes before the talk. They could be overheard shooing curious onlookers away shortly before Dias began speaking.

The results, published today in Nature, appear to show that a conventional conductor — a solid composed of hydrogen, nitrogen and the rare-earth metal lutetium — was transformed into a flawless material capable of conducting electricity with perfect efficiency.

While the announcement has been greeted with enthusiasm by some scientists, others are far more cautious, pointing to the research group’s controversial history of alleged research malfeasance. (Dias strongly denies the accusations.) Reactions by 10 independent experts contacted by Quanta ranged from unbridled excitement to outright dismissal, with many of the experts expressing some version of cautious optimism.

Previously, superconductivity has been observed only at frigid temperatures or crushing pressures — conditions that make those materials impractical for long-desired applications such as lossless power lines, levitating high-speed trains and affordable medical imaging devices. The newly forged compound conducts current with no resistance at 21 degrees Celsius (69.8 degrees Fahrenheit) and at a pressure of around 1 gigapascal. That’s still a lot of pressure — roughly 10 times the pressure at the deepest point in the Marianas Trench — but it’s more than 100 times less intense than the pressure required in previous experiments with similar materials.

“If it turns out to be correct, it’s possibly the biggest breakthrough in the history of superconductivity,” said James Hamlin, a physicist at the University of Florida who was not involved in the work. If it’s true, he said, “it’s an earth-shattering, groundbreaking, very exciting discovery.”

But incidents involving the team’s previous work — including but not limited to a near-room-temperature superconductivity claim published in Nature in 2020 and retracted late last year — have cast a shadow across today’s announcement. “It’s hard to not wonder if some of the same problems that have gone unaddressed in previous work also exist in the new work,” Hamlin said... (MORE - details)
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