{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"805408c4bdc438c381965aa20b35cfd74a988ca5356a148388611580eebfa118","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["53a5a16bf95de270ef07a8dec06d7765c4c62474854759438f7af841108ae502","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"73fd04c43dad712f8a4c6b755c835d602235fc4cf2ec5d345bb04cb7ec53a8ab","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.sr2ruo4.order-parameter","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"The pairing pattern of $\\mathrm{Sr_2RuO_4}$ must explain conflicting data: some measurements suggest a two-part order that breaks time-reversal symmetry, while others see only one transition.","posed_since":"1995","precise":"Determine the order parameter of $\\mathrm{Sr_2RuO_4}$ ($T_c = 1.5\\,\\mathrm{K}$): parity, spin structure, orbital and band content, and irreducible representation of D4h, consistent with the drop of the 17O Knight shift for in-plane fields (2019), the ultrasound jump in shear modulus $c66$ suggesting two components, muSR and polar Kerr time-reversal breaking, and no second heat-capacity anomaly under uniaxial stress. Candidates include d_xz + i d_yz, s' + i d_x2-y2, d + i g and interorbital pairing states.","problem_ref":"53a5a16bf95de270ef07a8dec06d7765c4c62474854759438f7af841108ae502","references":"","settled_by":"A single order parameter that quantitatively fits Knight shift, ultrasound, muSR, Kerr and strain-dependent heat capacity, confirmed by a phase-sensitive measurement.","status_note":"","title":"What is the superconducting order parameter of $\\mathrm{Sr_2RuO_4}$?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"45fdf1d4921c9309dcf388ee3abcb31774eff59d858a0cec00561532be3af59f","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c477a5510a68d12848ff17696ef82b84216b511951e4f01acb236265ceeea639","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"wk4Lr0B2fxqMqyKXJ9k4riNewfTRTmq4OOauFR3QjB5prOwV9ixlTo_kQqD4T4hsVsE1fp8QcF6FfCUjlo96Aw"},"schema":"pubphys.envelope/1"},"record_hash":"45fdf1d4921c9309dcf388ee3abcb31774eff59d858a0cec00561532be3af59f","leaf_index":3054}