{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"48464e0a7a771a6bf80cfd7b98bb3106fba196d4b4b10afba164f3642c03cdd3","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["14bc878649b69b8875db62824c319078a4d970be2cdb7b3112ce2367d6696176","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"d513c3fbaf9419e097bb64a22f036e8e9ab64e437b2c7adcb21f78682ba360de","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"cm.iron-based.nematic-driving-force","kind":"phenomenon","literature_status":"contested","n":"2","parents":[],"plain":"Electrons in iron-based materials spontaneously choose one crystal direction; it is debated whether magnetism, orbital occupation, or chemical bonds drive this choice, especially in FeSe where no magnetism follows.","posed_since":"","precise":"In iron pnictides and FeSe, determine whether $B1g$ electronic nematic order (measured by elastoresistance and Raman) is driven by spin fluctuations (vestigial order of stripe magnetism), by orbital order ($n_{xz} - n_{yz}$), or by bond order, and in particular explain nematic order at $T_s \\sim 90\\,\\mathrm{K}$ without magnetic order in FeSe. An answer is a theory consistent with the neutron spin-fluctuation spectrum, the ARPES orbital splitting and the absence of magnetic order in FeSe.","problem_ref":"14bc878649b69b8875db62824c319078a4d970be2cdb7b3112ce2367d6696176","references":"","settled_by":"A calculation reproducing $T_s$, the orbital splitting and the spin-fluctuation spectrum of FeSe and $\\mathrm{BaFe_2As_2}$ with one set of interaction parameters.","status_note":"","title":"What drives electronic nematic order in iron-based superconductors?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"76fe11f76020c236a58357691b0891ad6625981c391c0109625fb2fd7e6678d8","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a221e166fcf73004964baa503fa36e1ebd32976897146898aef869deaf88aeea","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"vaTAr1zy6FdsahaLEMAsCAS_tjtmHLFsmMc3pp8d7dxpG0aMTaAqphiWR-GEsOmn2vtb_cZvI026XFfIwTcCCQ"},"schema":"pubphys.envelope/1"},"record_hash":"76fe11f76020c236a58357691b0891ad6625981c391c0109625fb2fd7e6678d8","leaf_index":2880}