Dark matter accounts for approximately 85% of the universe’s total mass, yet its “invisibility” continues to challenge our understanding of physics. While the Standard Model has successfully described the structure of the visible universe, its limitations have driven scientists to explore ultralight exotic bosons—such as axions and dark photons—as motivative candidates for dark matter. Theoretical studies suggest that such new bosons could mediate exotic spin-dependent interactions beyond four fundamental forces, providing new avenues for detecting ultralight dark matter. However, terrestrial exotic-interaction searches have long been constrained by a fundamental trade-off: enhancing the signal of exotic spin interactions requires simultaneously increasing both the number of polarized spins and relative velocity, parameters that are inherently inversely coupled under laboratory conditions, leaving vast regions of theoretical parameter space unexplored.
Professor Xinhua Peng and Professor Min Jiang from the University of Science and Technology of China, in collaboration with multiple research institutions, have proposed the SQUIRE (Space-based QuantUm sensing for Interaction and exotic bosons Research Exploration) program—a space-based dark matter detection project. For the first time internationally, SQUIRE plans to deploy ultrasensitive quantum sensors aboard the China Space Station to search for potential exotic interactions mediated by dark matter candidate particles between the Earth’s geoelectron spins and the sensor spins. The scheme is projected to improve detection sensitivity by more than 7 orders of magnitude compared to terrestrial experiments. Furthermore, SQUIRE is expected to pave the way for a “space-ground integrated” quantum sensing network, opening new pathways for dark matter exploration in deep space. This paper was published on September 22 in National Science Review under the title “Quantum Sensors in Space: Unveiling the Invisible Universe.”
