Computers and Math from Science Daily Feed

Researchers at the University of Basel and the ETH in Zurich have succeeded in changing the polarity of a special ferromagnet using a laser beam. In the future, this method could be used to create adaptable electronic circuits with light.

As millions turn to ChatGPT and other AI chatbots for therapy-style advice, new research from Brown University raises a serious red flag: even when instructed to act like trained therapists, these systems routinely break core ethical standards of mental health care. In side-by-side evaluations with peer counselors and licensed psychologists, researchers uncovered 15 distinct ethical risks — from mishandling crisis situations and reinforcing harmful beliefs to showing biased responses and offering “deceptive empathy” that mimics care without real understanding.

Twisting atomically thin magnetic layers does more than reshape their electronics—it can create giant, topological magnetic textures. In chromium triiodide, researchers observed skyrmion-like patterns stretching far beyond the expected moiré scale, reaching hundreds of nanometers. Even more surprising, their size doesn’t simply follow the twist pattern but peaks at a specific angle. This twist-controlled magnetism could pave the way for low-power spintronic devices built from geometry alone.

Scientists have pulled off a feat long considered out of reach: getting light to mimic the famous quantum Hall effect. In their experiment, photons drift sideways in perfectly defined, quantized steps—just like electrons do in powerful magnetic fields. Because these steps depend only on nature’s fundamental constants, they could become a new gold standard for ultra-precise measurements. The discovery also hints at tougher, more reliable quantum photonic technologies.

Researchers have discovered new ways to shape quantum light, creating high-dimensional states that can carry much more information per photon. Using advanced tools like on-chip photonics and ultrafast light structuring, they’re pushing quantum communication and imaging into exciting new territory. Although long-distance transmission remains tricky, innovative approaches—such as topological quantum states—could make these fragile signals far more resilient. The momentum suggests quantum optics is entering a bold new phase.

Quantum computers need special materials called topological superconductors—but they’ve been notoriously difficult to create. Researchers have now shown they can trigger this exotic state by subtly adjusting the mix of tellurium and selenium in ultra-thin films. That tiny chemical tweak changes how electrons interact, effectively turning a quantum phase “dial” until the ideal state appears. The result is a more practical path toward building stable, next-generation quantum devices.

CU Boulder researchers have designed microscopic “racetracks” that trap and amplify light with exceptional efficiency. By using smooth curves inspired by highway engineering, they reduced energy loss and kept light circulating longer inside the device. Fabricated with sub-nanometer precision, the resonators rank among the top performers made from chalcogenide glass. The technology could lead to compact sensors, microlasers, and advanced quantum systems.