The National Institute of Information and Communications Technology (NICT) has successfully demonstrated entanglement swapping (one of the key quantum communication protocols) using sum-frequency generation (SFG) between single photons for the first time.

Although nonlinear optical effects of single photons have long been theoretically recognized as powerful tools for advancing quantum communication protocols, such effects are extremely weak at the single-photon level and had never been applied for quantum operations. By combining NICT’s state-of-the-art technologies including high-speed-clocked entangled photon-pair sources, low-noise superconducting nanowire single-photon detectors, and a high-efficiency nonlinear optical crystal, the research team succeeded in observing SFG between single photons with an unprecedented signal-to-noise ratio. Using this effect, they achieved the first experimental demonstration of entanglement swapping via single-photon SFG.

This achievement is expected to pave the way for miniaturized and efficient photonic quantum information processing circuit, as well as long-distance device independent quantum key distribution.

The results were published in Nature Communications on October 7, 2025 (Tuesday).

The Institute for Fusion Science installed the "Hyperspectral Camera for Auroral Imaging (HySCAI)" in Kiruna, Sweden, in May 2023 and commenced full-scale observations in September of the same year. A research group led by Professor Katsumi Iida and Assistant Professor Mikio Yoshinuma from the National Institute for Fusion Science, Professor Yusuke Ebihara from the Institute for Advanced Studies on Human Survival and Environmental Science at Kyoto University, and Professor Kazuo Shiokawa from the Institute for Space and Earth Environmental Research at Nagoya University has now succeeded in observing the altitude distribution of blue nitrogen ion (N₂⁺) auroras emitting light during astronomical twilight using HySCAI. This research developed a completely novel method, utilizing the phenomenon where the altitude at which sunlight illuminates the aurora changes as twilight progresses. This enabled precise observation of the altitude distribution of the nitrogen ion's emission intensity. The peak was found to be located at an altitude of approximately 200 km, exhibiting extremely high intensity.

Two formulations are at the heart of the study of turbulence: Kolmogorov’s universal framework for small-scale turbulence, which describes how energy propagates and dissipates through increasingly small eddies; and Taylor-Couette (TC) flows, which are very simple to create yet exhibit extremely complex behaviors, thereby setting the benchmark for the study of the fundamental characteristics of complex flows.

For the past many decades, a central contradiction between these potent formulations has plagued the field. Despite extensive experimental research and despite being found universal to almost all turbulent flows, Kolmogorov’s framework has apparently failed to apply to turbulent TC flows.

But now, after nine years developing a world-class TC setup at the Okinawa Institute of Science and Technology (OIST), researchers have finally resolved this tension by conclusively demonstrating that, contrary to the prevailing understanding, Kolmogorov’s framework does apply universally to the small scales of turbulent TC flows – precisely as predicted. 

Researchers from The University of Osaka have found that rituximab, a monoclonal antibody approved for the treatment of nephrotic syndrome in children in Japan, also improves disease management in adults. The drug kept adults with frequently relapsing nephrotic syndrome or steroid-dependent nephrotic syndrome relapse-free for longer, compared with placebo, with good safety. By reducing the frequency of relapses, rituximab may reduce the reliance on corticosteroids and help to improve quality of life among adult patients with these challenging conditions.

Translation factors eIF1A and eIF5B are key repressors of an abnormal protein translation process linked to neurodegenerative disorders, as reported by researchers from Science Tokyo. Using a human cell-free translation system, they reconstructed the aberrant translation of a mutated C9orf72 gene. This translation process revealed that the initiation factors (eIF1A and eIF1B) act at distinct checkpoints to suppress toxic protein synthesis implicated in frontotemporal dementia and amyotrophic lateral sclerosis.

Are we ready to live with caregiving robots? With Japan facing a projected shortage of 570,000 care workers by 2040, researchers at Chiba University surveyed older adults, families, caregivers, and developers about their acceptance of home-care robots. They found that openness to using robots influenced willingness among both users and developers, while other factors differed between the groups—revealing distinct perspectives and highlighting the need for collaboration and ethical awareness in developing home-care robots.