In a recent paper published in Physical Review D, the QUP research group has proposed a new search method that exploits the interaction between spin and dark matter in diamonds with nitrogen-vacancy centers. Using the nuclear spin of nitrogen, they have shown that the world's best limit can be placed on axions, a strong candidate for dark matter, in a wide range of signal frequencies below 100 Hz and masses below 10¹⁸th of the mass of an electron, the mass region which has not been well explored. By using different nitrogen isotopes, it is also possible to distinguish between the signals originating from dark matter and faint noise originating from environmental magnetic fields.

The paper shows that a diamond quantum sensor can be used to search for dark matter in a wide range of mass regions with high sensitivity by utilizing nuclear spins in addition to electron spins in diamond [1]. We expect to achieve even higher sensitivity by lowering the temperatures, developing new quantum sensing methods, and synthesizing high-quality diamonds. QUP is constructing a measurement system while working to increase sensitivity and explore a wide range of areas.

Published details
Journal: Physical Review D 111, 075028
Title: Nuclear spin metrology with nitrogen vacancy center in diamond for axion dark matter detection
Authors: So Chigusa, Masashi Hazumi, Ernst David Herbschleb, Yuichiro Matsuzaki, Norikazu Mizuochi, Kazunori Nakayama
DOI: https://doi.org/10.1103/PhysRevD.111.075028

Related paper
[1] Journal: Journal of High Energy Physics. 2025, 83 (2025).
Title: Light Dark Matter Search with Nitrogen-Vacancy Centers in Diamonds
Authors: So Chigusa, Masashi Hazumi, Ernst David Herbschleb, Norikazu Mizuochi, Kazunori Nakayama
DOI: https://doi.org/10.1007/JHEP03(2025)083

Related link
Press release from Kyoto University (in Japanese)
https://www.kuicr.kyoto-u.ac.jp/sites/topics/250516/
Press release from KEK (in Japanese)
https://www.kek.jp/wp-content/uploads/2025/05/pr202505161000diamond_.pdf
KEK News (in Japanese)
https://www.kek.jp/ja/press/202505161000diamond