Recently, a novel magnetic phase called altermagnetism has been proposed, ushering in a third distinct magnetic phase beyond ferromagnetism and antiferromagnetism. It is expected that this groundbreaking phase exhibits unique physical properties such as C-paired spin-valley locking, anomalous Hall effect, nontrivial Berry phase, and giant magnetoresistance, etc. Among all the predicted candidates, several room temperature altermagnets are suggested to host significant potential applications in the near future. Nevertheless, direct evidence about the spin pattern of the room temperature altermagnet is still unrevealed. Previous studies found that RuO2 is identified as the most promising candidate for room temperature d-wave altermagnetism, exhibiting a substantial spin splitting of up to 1.4 eV. In this study, utilizing angle-resolved photoemission spectroscopy (ARPES), we report experimental observation of the spin splitting in RuO2. Furthermore, employing spin-ARPES, we directly observed the d-wave spin pattern. Our results unequivocally show that RuO2 is a perfect d-wave altermagnet with great potential for upcoming spintronic applications.
Altermagnetic spin textures: Emergent electrodynamics, quantum geometry, and probes
Hearne Institute of Theoretical Physics, Department of Physics & Astronomy, Louisiana State University（路易斯安那州立大学物理与天文学系希恩理论物理研究所）；Institute for Theoretical Physics III, University of Stuttgart（斯图加特大学理论物理第三研究所）
Direct observation of quadruple spin-texture locking in a 2D d-wave altermagnet
Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（上海交大李政道研究所与物理天文学院）；Institute for Quantum Science and Technology, Shanghai University（上海大学量子科学与技术研究院）；Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）；Department of Physics, The Hong Kong University of Science and Technology（香港科技大学物理系）；Department of Physics, Southern University of Science and Technology（南方科技大学物理系）；State Key Laboratory of Micro-nano Engineering Science, Shanghai Jiao Tong University（上海交通大学微纳尺度工程科学国家重点实验室）；Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University（上海交通大学张江高等研究院）；Hefei National Laboratory（合肥国家实验室）；New Cornerstone Science Laboratory, Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所新基石科学实验室）
Southern University of Science and Technology (SUSTech)（南方科技大学）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；SOLARIS National Synchrotron Radiation Centre（索拉里斯国家同步辐射中心）；Southeast University（东南大学）；Hiroshima University（广岛大学）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）
Nanoscale imaging of spin textures with locally varying altermagnetic response in $α$-Fe$_2$O$_3$
Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM 2 ), Hiroshima University（广岛大学可持续性与打结手性超物质国际研究所）；Paul Scherrer Institut（保罗谢尔研究所）；ETH Zürich（苏黎世联邦理工学院）；Osaka Metropolitan University（大阪公立大学）；Helmholtz-Zentrum Berlin für Materialien und Energie GmbH（柏林亥姆霍兹材料与能源中心）；Universität of Augsburg（奥格斯堡大学）；RIKEN Center for Emergent Matter Science (CEMS)（理化学研究所涌现物质科学中心）；Diamond Light Source（英国钻石光源）
Topological spin textures in 2D altermagnetic chromium chalcogenides: Interplay between magnetic frustration and Dzyaloshinskii-Moriya interaction
Zhejiang Sci-Tech University（浙江理工大学）；Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation, Zhejiang Sci-Tech University（浙江量子态调控与光场操控重点实验室）
Key Role of Charge Disproportionation in Monoclinic Semiconducting Fe$_2$PO$_5$, a Room-Temperature d-Wave Altermagnet Candidate
Iowa State University（爱荷华州立大学）；South Dakota State University（南达科他州立大学）；University of Nebraska-Lincoln（内布拉斯加大学林肯分校）；Nebraska Center for Materials and Nanoscience（内布拉斯加材料与纳米科学中心）；Ames National Laboratory, U.S. Department of Energy（美国能源 Ames 国家实验室）
Extreme Strain Controlled Correlated Metal-Insulator Transition in the Altermagnet CrSb
KTH Royal Institute of Technology（瑞典皇家理工学院）；Leibniz Institute for Solid State and Materials Research, IFW Dresden（德累斯顿IFW莱布尼茨固体与材料研究所）；Center for High Pressure Science and Technology Advanced Research（高压科学与技术前沿研究中心）；Politecnico di Milano（米兰理工大学）；SLAC National Accelerator Laboratory（斯坦福直线加速器国家实验室）；Diamond Light Source（英国钻石光源）；Lund University（隆德大学）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）
Altermagnetic Signatures and Topological Textures in Ultrathin Multiferroic BiFeO$_3$
Brown University（布朗大学）；Cornell University（康奈尔大学）；Rice University（莱斯大学）；Rice Advanced Materials Institute, Rice University（莱斯大学先进材料研究所）；MAX IV Laboratory（MAX IV实验室）；University of Arkansas（阿肯色大学）；Johannes Gutenberg-University Mainz（美因茨约翰内斯·古腾堡大学）；Oak Ridge National Laboratory（橡树岭国家实验室）；Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；University of Augsburg（奥格斯堡大学）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；University of California, Berkeley（加州大学伯克利分校）；Tel Aviv University（特拉维夫大学）；Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；Czech Academy of Sciences（捷克科学院）；Kavli Institute at Cornell for Nanoscale Science, Cornell University（康奈尔纳米科学卡弗里研究所）；Leibniz-Institut für Kristallzüchtung（莱布尼兹晶体生长研究所）；Smalley-Curl Institute, Rice University（莱斯大学斯莫利-柯尔研究所）；Northeastern University（东北大学）
Above room temperature multiferroic tunnel junction with the altermagnetic metal CrSb
Huazhong University of Science and Technology（华中科技大学）；Florida State University（佛罗里达州立大学）；National High Magnetic Field Laboratory（国家强磁场实验室）；Charles University（查理大学）
Altermagnetism and Room-Temperature Metal-to-Insulator Transition in CsCr$_2$S$_2$O
Zhejiang University of Technology（浙江工业大学）；Zhejiang University（浙江大学）；Hangzhou Normal University（杭州师范大学）；Chinese Academy of Engineering Physics（中国工程物理研究院）；Bruker Scientific Instruments Co., Ltd（布鲁克科学仪器有限公司）；Zhejiang Laboratory（浙江实验室）；Nanjing University（南京大学）
Non-collinear Altermagnetic Phases in the Mott Insulator NiS$_2$
Leibniz Institute for Solid State and Materials Research（莱布尼茨固体与材料研究所）；Technische Universitat Dresden（德累斯顿工业大学）；Laboratoire Léon Brillouin, CEA, CNRS, Université Paris-Saclay（塞奈-萨克雷大学、法国原子能与替代能源委员会、法国国家科学研究中心勒昂布里渊实验室）；Université de Sherbrooke（舍布鲁克大学）；Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）；Regroupement Québécois sur les Matériaux de Pointe (RQMP)（魁北克尖端材料研究联合体）
Nonrelativistic and Relativistic Contributions to Spin-Momentum Locking and Spin Photogalvanic Effect in an Altermagnetic Multiferroic
University of Milan-Bicocca（米兰比可卡大学）；Consiglio Nazionale delle Ricerche (CNR-SPIN)（意大利国家研究委员会）；Institute of Physics, Polish Academy of Sciences（波兰科学院物理研究所）；Ca’ Foscari University of Venice（威尼斯大学）
Giant Room-Temperature Third-Order Electrical Transport in a Thin-Film Altermagnet Candidate
School of Materials Science and Engineering, Beihang University（北京航空航天大学材料科学与工程学院）；School of Physics, Beihang University（北京航空航天大学物理学院）；State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation, Beihang University（北京航空航天大学热带海洋工程材料与材料评价国家重点实验室）；National Synchrotron Radiation Laboratory, University of Science and Technology of China（中国科学技术大学国家同步辐射实验室）；Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences（中国科学院合肥物质科学研究院高磁场中心安徽低能量子材料与器件重点实验室）
From Narrow-gap Semiconductor to Metallic Altermagnet: Optical Fingerprints of Co-Doped FeSb$_2$
Universität Stuttgart（斯图加特大学）；Ruhr University Bochum（波鸿鲁尔大学）；Chinese Academy of Sciences（中国科学院）；Max Planck Institute for Solid State Research（马克斯·普朗克固体的研究所）；University of Maribor（马里博尔大学）
Cavity-induced coherent magnetization and polaritons in altermagnets
Georgetown University（乔治城大学）；Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；Institute of Physics, Czech Academy of Sciences（捷克科学院物理研究所）
Revealing the origin of XMCD in an altermagnet via three-dimensional control of spins
University of Oxford（牛津大学）；Diamond Light Source（钻石光源）；Technical University of Darmstadt（达姆施塔特工业大学）；Durham University（杜伦大学）；Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay（阿尔伯特·费尔特实验室，法国国家科学研究中心，泰雷兹集团，巴黎萨克雷大学）；ALBA Synchrotron Light Facility, CELLS（ALBA同步辐射光源设施，CELLS）
Eastern Institute for Advanced Study, Eastern Institute of Technology（东方高等研究院，东方理工大学）；School of Physical Science and Technology, Suzhou University of Science and Technology（苏州科技大学物理科学与技术学院）；Department of Physics, University at Buffalo, State University of New York（纽约州立大学布法罗分校物理系）
Correlation-Driven Orbital Order Realizes 2D Metallic Altermagnetism
Indian Institute of Technology Kanpur（坎普尔印度理工学院）；Johannes Gutenberg Universität Mainz（美因茨约翰内斯·古腾堡大学）；National Institute of Science Education and Research（国家科学教育与研究所）
Spin Hall and Edelstein Effects in Novel Chiral Noncollinear Altermagnets
Leibniz Institute for Solid State and Materials Research, IFW Dresden（德累斯顿莱布尼茨固体与材料研究所）；Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体的化学物理学研究所）；Laboratoire Léon Brillouin, CEA, CNRS, Université Paris-Saclay（里昂·布里渊实验室，法国原子能委员会，法国国家科学研究中心，巴黎萨克雷大学）；Würzburg-Dresden Cluster of Excellence Ct.qmat, Technische Universitat Dresden（维尔茨堡-德累斯顿卓越集群Ct.qmat，德累斯顿工业大学）；Département de Physique et Institut Quantique, Université de Sherbrooke（舍布鲁克大学物理系与量子研究所）；Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）
Chiral Phonons Coupled to Spin-Split Bands in Altermagnetic CrSb and MnTe
CNR - Istituto Officina dei Materiali (IOM)（意大利国家研究委员会材料研究所）；Universität Würzburg（维尔茨堡大学）；Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna（博洛尼亚大学物理与天文学系）
Altermagnetism, ARPES, symmetry, non-relativistic band splitting
Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences（中国科学院上海微系统与信息技术研究所）；University of Chinese Academy of Sciences（中国科学院大学）；National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China（中国科学技术大学核科学与技术学院及国家同步辐射实验室）；Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute（上海先进应用研究院上海同步辐射光源）
Coupled Real- and Momentum-Space Topology in Symmetry-Locked Bilayer Altermagnet
Hebei University of Technology（河北工业大学）；Arizona College of Technology at Hebei University of Technology（河北工业大学亚利桑那科技学院）；Hebei Engineering Laboratory of Photoelectronic Functional Crystals, Hebei University of Technology（河北工业大学光电功能晶体河北省重点实验室）
Novel 2D Altermagnetic Vanadium Oxide with a Buckled Lieb Structure
UNAM - National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University（比尔肯特大学纳米技术与材料科学研究所）；Linköping University（林雪平大学）；Uppsala University（乌普萨拉大学）；University of Iowa（爱荷华大学）
基于密度泛函理论第一性原理计算，发现单层V₂O晶体在翘曲Lieb晶格中是一种二维交变磁性材料，具有负泊松比、面外易磁化轴、1.2 eV动量依赖自旋劈裂以及大贝里曲率和约40 (ℏ/e) S cm⁻¹的自旋霍尔电导率。
Strain-Tunable Shift Current and Magneto-Optical Kerr Effect in Multiferroic Altermagnet Fe2Mo3O8
Jilin University（吉林大学）；Suzhou Laboratory（苏州实验室）；Institute of Materials Science, Technology University of Darmstadt（达姆施塔特工业大学材料科学研究所）；University of Salzburg（萨尔茨堡大学）；College of Physics, Jilin University（吉林大学物理学院）
Atomic-scale visualization of d-wave altermagnetism
Tsinghua University（清华大学）；Frontier Science Center for Quantum Information（量子信息前沿科学中心）；Beijing Institute of Technology（北京理工大学）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）；Southern University of Science and Technology（南方科技大学）；Hefei National Laboratory（合肥国家实验室）
Intrinsic Spin Filter Effect in a $d$-wave altermagnet KV$_2$Se$_2$O with Open Fermi Surface
School of Science, Sun Yat-sen University（中山大学理学院）；Department of Physics and Astronomy, University of Florence（佛罗伦萨大学物理与天文学系）；Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院人工微结构和量子调控教育部重点实验室）；The State Key Laboratory for Refractories and Metallurgy, Wuhan University of Science and Technology（武汉科技大学耐火材料与冶金国家重点实验室）；Laboratory for Computational Physical Sciences (MOE), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University（复旦大学物理系表面物理国家重点实验室计算物理科学教育部重点实验室）；Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University（中山大学广东省磁电物理与器件重点实验室）
