{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"d153932d207e210706725d51e175c4ee828c869f3d6cd8ebf81da2046f296d85","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"84ef6aa0f69712024d2d096f23d3dd76ab814fa2c0c6009a0c247255eedff915","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"cm.heavy-fermions.kondo-breakdown-vs-sdw","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"At a heavy-fermion quantum critical point either magnetism appears while the f electrons stay bound to conduction electrons, or the binding itself (Kondo screening) breaks down; which happens decides the theory.","posed_since":"2001","precise":"For heavy-fermion quantum critical points (CeCu6-xAux, YbRh2Si2, CeRhIn5 under pressure, CeCoIn5), determine whether criticality is of Hertz-Millis-Moriya spin-density-wave type with Kondo screening intact, or of local (Kondo breakdown) type in which the f electrons leave the Fermi volume at the critical point. An answer classifies the known materials using $\\omega/T$ scaling of the dynamical spin susceptibility, the Fermi-volume change, and the exponents of $C/T$ and $\\rho(T)$.","problem_ref":null,"references":"","settled_by":"Material-by-material measurements of Fermi volume on both sides of the critical point plus dynamical spin susceptibility scaling, compared with the two theories.","status_note":"","title":"Kondo breakdown versus spin-density-wave criticality in heavy-fermion metals","topic_ref":"348f0bf7a34a765b71c6ebd8ae84e9439d4dfb5f6e2b08600fcf48a04710cc34"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1f601410322cdcfe00cccad7c945bff94b200a5feac304a2341ddec819eedea6","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"6faa76cd3ca13ea5af18bcb5c56034ed39a02b0a1a43dd9173c3a1bcfcd20a95","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"sTBRsATTHIWuVdft7xOYklVXlheL0iACaLaVMQ_6OHi080m021gTX9jCg-JPpXQMhYjdlN-bGXbYBs0VMkbLDQ"},"schema":"pubphys.envelope/1"},"record_hash":"1f601410322cdcfe00cccad7c945bff94b200a5feac304a2341ddec819eedea6","leaf_index":1013}