We demonstrate that ultralight axion dark matter with a coupling to photons induces an oscillating global terrestrial magnetic field signal in the presence of the background geomagnetic field of the Earth. This signal is similar in structure to that of dark-photon dark matter that was recently pointed out and searched for in [arXiv:2106.00022] and [arXiv:2108.08852]. It has a global vectorial pattern fixed by the Earth's geomagnetic field, is temporally coherent on long time scales, and has a frequency set by the axion mass $m_a$. In this work, we both compute the detailed signal pattern, and undertake a search for this signal in magnetometer network data maintained by the SuperMAG Collaboration. Our analysis identifies no strong evidence for an axion dark-matter signal in the axion mass range $2\times10^{-18}\text{eV} \lesssim m_a \lesssim 7\times10^{-17}\text{eV}$. Assuming the axion is all of the dark matter, we place constraints on the axion-photon coupling $g_{aγ}$ in the same mass range; at their strongest, for masses $3\times 10^{-17}\text{eV} \lesssim m_a \lesssim 4\times 10^{-17}\text{eV}$, these constraints are comparable to those obtained by the CAST helioscope.
Dark Matter Detection through Rydberg Atom Transducer
Southern University of Science and Technology（南方科技大学）；International Shenzhen Quantum Academy（深圳国际量子研究院）；Peking University（北京大学）；Beijing Laser Acceleration Innovation Center（北京激光加速创新中心）；City University of Hong Kong（香港城市大学）；City University of Hong Kong Shenzhen Research Institute（香港城市大学深圳研究院）；Nanjing University（南京大学）
Momentum and Matter Matter for Axion Dark Matter Matters on Earth
University of Maryland, College Park（马里兰大学帕克分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Berkeley Center for Theoretical Physics, University of California, Berkeley（加州大学伯克利分校理论物理中心）；Université de Strasbourg（斯特拉斯堡大学）；CNRS（法国国家科学研究中心）；IPHC UMR7178（高能物理研究所）；Université de Genève（日内瓦大学）；Weizmann Institute of Science（魏茨曼科学研究所）；The University of Sydney（悉尼大学）
Signature of axion dark matter in low-frequency terrestrial electromagnetic fields: formulation and predictions
Center for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto University（京都大学 引力物理学与量子信息中心，汤川理论物理研究所）；Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, The University of Tokyo（东京大学 东大高等研究院 宇宙物理数学研究所）；Korea Institute for Advanced Study（韩国高等科学研究院）；Physics Program, Graduate School of Advanced Science and Engineering, Hiroshima University（广岛大学 先进理工学研究科 物理项目）；Astrophysical Science Center, Hiroshima University（广岛大学 天体物理科学中心）；Department of Liberal Arts and Basic Sciences, College of Industrial Technology, Nihon University（日本大学 产业技术学部 教养与基础科学系）
School of Instrumentation and Optoelectronic Engineering, Beihang University（北京航空航天大学仪器科学与光电工程学院）；International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP, WPI), High Energy Accelerator Research Organization (KEK)（高能加速器研究机构（KEK）宇宙与粒子研究量子场测量系统国际中心（WPI））；Quantum Science and Engineering Centre, Nanyang Technological University（南洋理工大学量子科学与工程中心）；School of Physical and Mathematical Sciences, Nanyang Technological University（南洋理工大学物理与数学科学学院）；CERN, Theoretical Physics Department（欧洲核子研究中心理论物理部）；Physics Department, Technion - Israel Institute of Technology（以色列理工学院物理系）；Quantum Science and Technology College, Beihang University（北京航空航天大学量子科学与技术学院）；Hefei National Laboratory（合肥国家实验室）
Wide-Mass-Scanning-Range Setup and Phase-Resolved Protocol for Axion Dark Matter Detection
Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité（巴黎高等师范学院物理实验室）；Laboratoire de Physique et d’Etude des Matériaux, ESPCI Paris, PSL University, CNRS, Sorbonne Université（ESPCI巴黎学院物理与材料研究实验室）；Institute of Astrophysics, FORTH（希腊基础与研究基金会天体物理研究所）
Enhancing Constraints on Ultralight Axion Dark Matter from Gravitational Capture
University of California Santa Cruz（加州大学圣克鲁兹分校）；Princeton University（普林斯顿大学）；Argonne National Laboratory（阿贡国家实验室）；University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；The University of Tokyo（东京大学）
Search for Ultralight Dark Matter with Quantum Magnetometry in the Earth's Cavity
Nanjing Normal University（南京师范大学）；Jiangxi Normal University（江西师范大学）；Beihang University（北京航空航天大学）；Peking University（北京大学）；Beijing University of Technology（北京工业大学）；Hangzhou Institute of Extremely-Weak Magnetic Field Major National Science and Technology Infrastructure（杭州弱磁大科学装置国家重大科技基础设施研究院）；Henan Normal University（河南师范大学）；Chinese Academy of Sciences（中国科学院）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；University of Science and Technology of China（中国科学技术大学）；Yantai University（烟台大学）
Magnetic Turbulence Boosts Supernova Signals of Axion-Photon Conversion
Istituto Nazionale di Fisica Nucleare (INFN)（意大利国家核物理研究所）；Gran Sasso Science Institute (GSSI)（格兰萨索科学研究所）；Università degli Studi di Padova（帕多瓦大学）；Max-Planck-Institut für Physik（马克斯·普朗克物理研究所）
Axion-induced effects in atoms, molecules and nuclei: Parity nonconservation, anapole moments, electric dipole moments, and spin-gravity and spin-axion momentum couplings
