{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2a020c6a5b4cb86ac9cf1ac2b050ae8304e67fa1597a58352270fffe693c0ac6","created":"2026-10-03T07:17:59Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"ead41c47dcf1e8e841e13d6029662510838315c3520f7ff361238e596c0593d8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"cm.dilute-superconductivity.yptbi-j32-pairing","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"In the half-Heusler compound YPtBi, the electrons near the Fermi level carry total angular momentum $3/2$ instead of the usual $1/2$, so a pair can have total angular momentum 0, 1, 2 or 3, not only the usual 0 or 1. Experiments indicate lines of zero gap, but which pairing state forms is unknown.","posed_since":"2016","precise":"YPtBi ($\\Gamma_{8}$ band, $n \\sim 2e18\\ \\mathrm{cm}^{-3}$, $T_{c} \\sim 0.78\\ \\mathrm{K}$) shows a penetration depth linear in $T$ suggesting line nodes (Kim et al., Science Advances 2018) and an upper critical field above the Pauli limit. Identify the order parameter among $j = 3/2$ pairing channels (septet $J = 3$, quintet $J = 2$, singlet-septet mixture allowed by broken inversion) and its pairing interaction. An answer is a symmetry identification consistent with penetration depth, NMR, critical-field and tunneling data.","problem_ref":null,"references":"","settled_by":"Phase-sensitive or angle-resolved gap measurements (e.g. field-angle thermal conductivity or Josephson interferometry) that discriminate between the $J = 2$ and $J = 3$ candidate states.","status_note":"","title":"Pairing state of total angular momentum $3/2$ fermions in YPtBi","topic_ref":"1691597bf36b5c4ae6e8e76cab311c80818c254bf6df91fc1604cdef43bb8e76"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"1556471aceff89e4ac7ba529a6a220bdd6a394873c0015f3b653bed4823e071c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4ec665bee9b2c1565a9c0a2322c0b466c755f29d132e095d9592746431b6ec0a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"aSpiAuQAzIs5vfo6y-huasupJZ8WmOq__D5ok5YBzIit-9QFiNMhVH9oQNERnnXVH8jLAg28WPs0YBcAaIMFAA"},"schema":"pubphys.envelope/1"},"record_hash":"1556471aceff89e4ac7ba529a6a220bdd6a394873c0015f3b653bed4823e071c","leaf_index":948}