{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b31b3abc626561c39175d580b311251a46e5897aaa47aee2f911ed0e348a8fa4","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"913c1565d77c847a704a471602fb2c0366d3941506d215e1fabe569112eeb3b8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.kitaev-materials.rucl3-spin-hamiltonian","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Interpreting any $\\alpha$-RuCl3 experiment requires its spin couplings, yet published fits disagree even on which coupling is largest. Without an agreed set, claims of spin-liquid behavior cannot be checked against theory.","posed_since":"","precise":"Determine the exchange constants of alpha-RuCl3 in H = sum over nearest-neighbor bonds <ij> of type gamma of [J S_i . S_j + K S^gamma_i S^gamma_j + Gamma (S^alpha_i S^beta_j + S^beta_i S^alpha_j) + Gamma' (terms mixing gamma with alpha and beta)] + J3 sum over third neighbors of S_i . S_j, with $(\\alpha, \\beta, \\gamma)$ a permutation of $(x, y, z)$, from a joint fit of inelastic neutron spectra, THz and ESR modes, the field-angle dependence of the critical field and the high-field magnon spectrum. An answer is one parameter set with error bars consistent with all these data, including the sign of $K$ and the ratio $K/\\Gamma$.","problem_ref":null,"references":"","settled_by":"A global fit of neutron, THz, ESR, magnetization and magnetostriction data using quantum many-body (beyond linear spin-wave) calculations of the spectra that yields a unique parameter set.","status_note":"Proposed parameter sets range from Kitaev dominated to regions with a large off-diagonal $\\Gamma$ term; Maksimov and Chernyshev (Physical Review Research 2020) argued for the latter.","title":"The minimal spin Hamiltonian of $\\alpha$-RuCl3","topic_ref":"8a920d20c87cdaf1da8d81ec58f05a8787f99b7ca6e234e7f5eef3a4d6c67048"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"dd0e9821c69027dfa25a1569e5f3d8c9d179cda67bd7ec39e5ca03e298f1676e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8b50e79e8ef6a6054fc4d5aad5e81e71678155dbfffcdb023ec2644288a27e86","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"dcDlec6eFX1nqIGwMpD5R4uD9Yj8nCAU27fZNd7QQNMkq3UwkHKlkb87UkFT-JVpXJJjZugiBOZIQvFnKucRAQ"},"schema":"pubphys.envelope/1"},"record_hash":"dd0e9821c69027dfa25a1569e5f3d8c9d179cda67bd7ec39e5ca03e298f1676e","leaf_index":1057}