On January 15, 2026, scientists from the Chinese mainland at the University of Chinese Academy of Sciences (UCAS) made history: they directly observed the long-theorized Migdal effect for the first time! 🎉🔬 This breakthrough could open a new window in the global hunt for light dark matter.
The Migdal effect was predicted back in 1939 by Soviet physicist Arkady Migdal. It describes how an atom, jolted by a neutral particle (like dark matter), releases electrons as its nucleus recoils and the electron cloud lags behind. For decades, this idea lacked direct proof, making it tricky to use in dark matter searches.
Professor Liu Qian and her team at UCAS designed an ultra-sensitive 'camera' by combining a micro-pattern gas detector with a pixelated readout chip. They used a compact deuterium-deuterium generator to fire neutrons at the detector's gas, creating tiny nuclear recoils and the elusive Migdal electrons. What showed up were paired tracks sharing the same starting point – an unmistakable signature! 👀
By filtering out background noise from gamma rays and cosmic radiation, the researchers confirmed these 'Migdal events' as genuine. Their results, published in Nature, fill a key gap in experimental physics and solidify the Migdal effect's role in future dark matter experiments.
Yue Qian of the China Dark Matter Experiment (CDEX) said this work not only proves a longstanding theory but also highlights the Chinese mainland's strength in high-precision detector tech. Next up, the team plans to team up with global dark matter groups to build next-generation detectors based on these findings.
'Dark matter holds the key to understanding our universe's origin and evolution,' said Professor Zheng Yangheng, a core member of the project. 'With this discovery, we're one step closer in the cosmic treasure hunt! 🪐✨'
Reference(s):
Chinese scientists achieve first direct observation of Migdal effect
cgtn.com
