{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"403707a74c789e3e2e130985b0ccb72a84af184fdcf92ace035278266d7715a4","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["1ded679c5ad8b8ea375c402469b19aa10eda14eeafcea7513745efd2fc8cc18d","5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"b9e5a458cab4a585a1ed744862d2f2916d07eafa1470dfbbe0ac0b5d0e636c22","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.light-induced-sc.k3c60-diamagnetism","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"1ded679c5ad8b8ea375c402469b19aa10eda14eeafcea7513745efd2fc8cc18d","relation":"special_case"}],"plain":"Superconductors push out magnetic fields (the Meissner effect). A measurement on light-driven K3C60 has so far only set a limit on this effect.","posed_since":"","precise":"Measure the transient volume susceptibility $\\chi_v$ of K3C60 at $T > 20\\ \\mathrm{K}$ after mid-infrared excitation; complete expulsion is $\\chi_v = -1/(4\\pi)$ in CGS, reduced by the excited volume fraction. Answer yes or no: is $\\chi_v(t, T)$ distinguishable from zero within its uncertainty and consistent with superconducting diamagnetism of the excited volume?","problem_ref":null,"references":"","settled_by":"Time-resolved magneto-optic or nitrogen-vacancy magnetometry on single crystals or dense films with better field resolution than the 2025 powder measurement.","status_note":"A 2025 Faraday-rotation search on powders (De Vecchi et al., arXiv:2502.20276) bounded the response to less than about 10 percent of complete expulsion, which does not decide the question.","title":"Does photoexcited K3C60 above $T_{c}$ expel magnetic field","topic_ref":"a4f7f1ae5dbd43b5f6c513a7a2b6e1f0d22cc39b03da4e8f25e23fa5acb4d309"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"62a701b99f658e98e4fb13cdc63ce8564ca3644b7ee696819ee52c213bae791b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8ee6da19c46bc3e30739955016ee5ba69837f3e1d70f06c38236dbb535c04455","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"oK1Ier5vh9Vz5mqKpjhi7sKbqP65CVM9DjgQHHX0DRGd4LDJWXWyo_1qedp25ECEs8Z-7JVzOxJpyPKuUuM1DQ"},"schema":"pubphys.envelope/1"},"record_hash":"62a701b99f658e98e4fb13cdc63ce8564ca3644b7ee696819ee52c213bae791b","leaf_index":1066}