{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0ba1926cf10b387c6464e1dae6e1390ff38a7fb11301a4838ca38ccda59800e9","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["c6b4d2931e6c107dea5a127316de0338f5285234e58f980d6ed89323002c63e6","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"8d04a2e196689ffc3bf66965301d22899d60fbaf255a5fbc208b7801d1b32aea","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.altermagnets.ruo2-magnetic-state","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"$\\mathrm{RuO_2}$ was the first proposed metallic altermagnet, but muon and neutron measurements find no magnetic order in bulk crystals. Signals reported in thin films might come from surfaces or defects.","posed_since":"","precise":"Determine whether stoichiometric rutile $\\mathrm{RuO_2}$ has collinear antiferromagnetic order with Ru moment above $10^{-3}\\,\\mu_B$, in bulk and in epitaxial films; if not, identify the origin of the anomalous Hall, spin-splitting torque and spin-resolved ARPES signals reported in films. An answer is a moment value or upper bound per sample type and a mechanism for the film signals.","problem_ref":"c6b4d2931e6c107dea5a127316de0338f5285234e58f980d6ed89323002c63e6","references":"","settled_by":"Muon, neutron and resonant x-ray measurements on the same films used for transport, combined with depth-resolved magnetic probes.","status_note":"Muon spin rotation and neutron diffraction (2024, arXiv:2405.10820) bound the bulk moment near $10^{-4}\\,\\mu_{\\mathrm{B}}$ per Ru; a 2026 preprint (arXiv:2604.10659) attributes film signals to surface ferrimagnetism.","title":"Is $\\mathrm{RuO_2}$ an altermagnet?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d160b8db17e992f384e4ab21e7ad7086a855ed4183eedf79c582c25cfb47df47","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2a7aa1cec8eaebf6b3156ea0305f493050084d3112146ca8e0ccc90ed9df5c46","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"3ZKu2Pm5MBHPcZZaVGNj3c-BDyyXyacZo6Ge9HgmBJ8rit2RHWJcfJ_4BgS4Nw9BOrT_h80etpKy6RcJKClZCg"},"schema":"pubphys.envelope/1"},"record_hash":"d160b8db17e992f384e4ab21e7ad7086a855ed4183eedf79c582c25cfb47df47","leaf_index":2692}