Long, C., Huang, M., Ye, X. et al. Hybrid quantum-classical-quantum convolutional neural networks. Sci Rep 15, 31,780 (2025). https://doi.org/10.1038/s41598-025-13417-1
Category: quantum physics – Page 7
Quantum entanglement lasts 600 times longer in elusive dark states, study finds
A research team affiliated with UNIST has successfully demonstrated the experimental creation of collective quantum entanglement rooted in dark states—previously confined to theoretical models. The findings are published online in Nature Communications.
Unlike bright states, dark states are highly resistant to external disturbances and exhibit remarkably extended lifetimes, making them promising candidates for next-generation quantum technologies such as quantum memory and ultra-sensitive sensors.
Led by Professor Je-Hyung Kim in the Department of Physics at UNIST, in collaboration with Dr. Changhyoup Lee from the Korea Research Institute of Standards and Science (KRISS) and Dr. Jin Dong Song from the Korea Institute of Science and Technology (KIST), the team has achieved the controlled induction of dark state-based collective entanglement. Remarkably, this entanglement exhibits a lifetime approximately 600 times longer than that of conventional bright states.
Something from nothing: Physicists model vacuum tunneling in a 2D superfluid
In 1951, physicist Julian Schwinger theorized that by applying a uniform electrical field to a vacuum, electron-positron pairs would be spontaneously created out of nothing, through a phenomenon called quantum tunneling.
The problem with turning the matter-out-of-nowhere theory into Star Trek replicators or transporters? Enormously high electric fields would be required—far beyond the limits of any direct physical experiments.
As a result, the aptly-named Schwinger effect has never been seen.
Graphene reveals electrons that behave like frictionless fluid and break textbook rules
For several decades, a central puzzle in quantum physics has remained unsolved: Could electrons behave like a perfect, frictionless fluid with electrical properties described by a universal quantum number?
This unique property of electrons has been extremely difficult to detect in any material so far because of the presence of atomic defects, impurities, and imperfections in the material.
Researchers at the Department of Physics, Indian Institute of Science (IISc), along with collaborators from the National Institute for Materials Science, Japan, have now finally detected this quantum fluid of electrons in graphene—a material consisting of a single sheet of pure carbon atoms.
Probability theorem gets quantum makeover after 250 years
How likely you think something is to happen depends on what you already believe about the circumstances. That is the simple concept behind Bayes’ rule, an approach to calculating probabilities, first proposed in 1763. Now, an international team of researchers has shown how Bayes’ rule operates in the quantum world.
“I would say it is a breakthrough in mathematical physics,” said Professor Valerio Scarani, Deputy Director and Principal Investigator at the Center for Quantum Technologies, and member of the team. His co-authors on the work published on 28 August 2025 in Physical Review Letters are Assistant Professor Ge Bai at the Hong Kong University of Science and Technology in China, and Professor Francesco Buscemi at Nagoya University in Japan.
“Bayes’ rule has been helping us make smarter guesses for 250 years. Now we have taught it some quantum tricks,” said Prof Buscemi.