Intercity quantum sensor network tightens axion dark matter constraints

February 2, 2026 Intercity quantum sensor network tightens axion dark matter constraints by Ma Hanyue, University of Science and Technology of China edited by Gaby Clark, reviewed by Robert Egan Gaby Clark scientific editor Meet our editorial team Behind our editorial process Robert Egan associate editor Meet our editorial team Behind our editorial process Editors' notes This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: fact-checked peer-reviewed publication trusted source proofread The GIST Add as preferred source Nuclear-spin distributed network. Credit: Nature (2026). DOI: 10.1038/s41586-025-10034-w Recently, scientists from institutions including the University of Science and Technology of China made a fundamental breakthrough in nuclear-spin quantum precision measurement. They developed the first intercity nuclear-spin-based quantum sensor network, which experimentally constrains the axion topological-defect dark matter and surpasses the astrophysical limits. The study is published in the journal Nature. Current studies indicate that ordinary visible matter accounts for only about 4.9% of the universe, while dark matter makes up about 26.8%. Axions are among the best-motivated dark matter candidates, and axion fields can form topological defects during phase transitions in the early universe. As Earth crosses topological defects, the defects are expected to interact with nuclear spins and induce signals. However, detection remains a formidable challenge because signals are extremely weak and short-duration. To overcome the detection challenge, the research team innovatively developed a nuclear-spin quantum precision measurement that "stores" microsecond-scale axion-induced signals in a long-lived nuclear-spin coherent state, enabling a minute-scale readout signal. At the same time, the team used nuclear spin as a quantum spin amplification to further enhance the weak dark-matter signal by at least 100-fold, increasing the sensitivity of spin rotation to about 1 μrad, representing an improvement of more than four orders of magnitude over previous techniques. Furthermore, researchers created the first intercity nuclear-spin-based quantum sensor network to discriminate dark matter signals. The network consists of five nuclear-spin quantum sensors geographically distributed across Hefei and Hangzhou with a baseline distance of approximately 320 km, which are synchronized using global positioning system (GPS) time. Though no statistically significant topological defect crossing event was recorded during two months of observation, the team set the most stringent constraints on the axion-nucleon coupling across an axion mass range from 10 peV to 0.2 μeV, achieving 4.1 × 1010 GeV at 84 peV. Notably, as the first laboratory experiment to surpass astrophysical constraints on axion topological-defect dark matter, the study opens up the possibility of examining previously unexplored parameter space. At the interface of quantum precision measurement and fundamental physics, this breakthrough not only provides a new route to probe topological defect dark matter, but also offers a new direction for searches on broad beyond-Standard Model physics such as axion stars and axion strings.

The team is planning to boost sensitivity by another four orders of magnitude in the future by building a global network, extending deployments into space, and developing next-generation technology. Publication details Yuanhong Wang et al, Constraints on axion dark matter by distributed intercity quantum sensors, Nature (2026). DOI: 10.1038/s41586-025-10034-w Journal information: Nature Key concepts Hypothetical particles Provided by University of Science and Technology of China Citation: Intercity quantum sensor network tightens axion dark matter constraints (2026, February 2) retrieved 9 February 2026 from https://phys.org/news/2026-02-intercity-quantum-sensor-network-tightens.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Scientists discover 'levitating' time crystals that you can hold in your hand Feb 6, 2026 3 New study uses Neanderthals to demonstrate gap between generative AI and scholarly knowledge Feb 6, 2026 0 What to watch as fungal infections rise: Species that can quickly 'translate' fat-use proteins Feb 7, 2026 1 A dinosaur with spikes exhibiting unprecedented properties discovered in China Feb 6, 2026 0 The 'Little red dots' observed by Webb were direct-collapse black holes Feb 8, 2026 3 Nanodevice tugs single proteins to reveal how cells sense force 8 minutes ago Why does rough grinding make stainless steel more prone to corrosion? 8 minutes ago Why only a small number of planets are suitable for life 15 minutes ago Tiny Enceladus exercises giant electromagnetic influence at Saturn 17 minutes ago A smashing success: Relativistic Heavy Ion Collider wraps up final collisions 28 minutes ago 5,300-year-old 'bow drill' rewrites story of ancient Egyptian tools 48 minutes ago Why elite chess ratings get stuck: A new model treats draws as data 1 hour ago Physicists clarify key mechanism behind energy release in molybdenum-93 1 hour ago Scientists harness nature's chirality bias to design series of complex mechanically interlocked molecules 2 hours ago Quantum dots reveal entropy production, a key measure of nanoscale energy dissipation 2 hours ago Using quantum technology to constrain new particles Jul 29, 2022 New spin amplifier accelerates search for dark matter Dec 13, 2021 Using a Floquet quantum detector to constrain axion-like dark matter Feb 8, 2022 Hunting for dark matter axions with a quantum-powered haloscope Dec 30, 2025 Researchers unveil axion-torsion coupling via dark photons Jun 3, 2025 Review of noble-gas spin amplification via spin-exchange collisions Sep 26, 2022 A smashing success: Relativistic Heavy Ion Collider wraps up final collisions 28 minutes ago Physicists clarify key mechanism behind energy release in molybdenum-93 1 hour ago Quantum dots reveal entropy production, a key measure of nanoscale energy dissipation 2 hours ago Scientists discover 'levitating' time crystals that you can hold in your hand Feb 6, 2026 Quantum encryption method demonstrated at city-sized distances for the first time Feb 6, 2026 Quantum Twins simulator unveils 15,000 controllable quantum dots for materials research Feb 6, 2026