{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c9fa10ede67b41020bcd9cc74fde4f2403bf787a9b5abd06c861d6993bf9ed17","created":"2026-10-03T07:18:01Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"430284ae4e4e6939e342af4d0740c9b5b18eeadaba7dbe2099a18d2c1afae155","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"cm.spin-ice.pi-flux-classification","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Quantum spin ice comes in two versions, labeled zero-flux and pi-flux, that differ in how emergent charges feel the internal magnetic field. Which version each cerium compound realizes depends on the signs of its exchange couplings, which are still debated.","posed_since":"","precise":"For Ce2Zr2O7, Ce2Sn2O7 and Ce2Hf2O7 described by the dipolar-octupolar Hamiltonian H = sum_<ij> [J_x tau^x_i tau^x_j + J_y tau^y_i tau^y_j + J_z tau^z_i tau^z_j + J_xz (tau^x_i tau^z_j + tau^z_i tau^x_j)], determine the exchange parameters and the sign of the dominant transverse coupling that fixes the zero-flux or $\\pi$-flux $U(1)$ phase, and confirm it by the predicted spinon-continuum structure. An answer is the classification per compound with fitted parameters.","problem_ref":null,"references":"","settled_by":"Global fits of neutron spectra, heat capacity and magnetization in field to the XYZ model, compared with the distinct spinon spectra of each flux phase.","status_note":"Gao et al. (2025) classify Ce2Zr2O7 as pi-flux; parameter fits differ across groups and compounds.","title":"Zero-flux or pi-flux quantum spin ice in cerium pyrochlores?","topic_ref":"52cddd9c3d75748e46e41f34a20edd20c81c928cc0056fa7e4de59ade0220e82"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f282a8930978eb748e2f875a7c24ea2da93a36b7f78757e6b7832deb0faf0f08","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"17ffb67a5252233ed799ba31eb3843efa89d09bc550cd9c7344ca6e5e0112902","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"IGxJtIw6jC-r3dRYXRW-pQo-e1GtuzEzeTv-FvGretwm4dMcTqX4qbeVJf4TpZy_szL3TqjX8xdWqh0F81vrBA"},"schema":"pubphys.envelope/1"},"record_hash":"f282a8930978eb748e2f875a7c24ea2da93a36b7f78757e6b7832deb0faf0f08","leaf_index":1173}