{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"3cd162a09511382c8c26df1d49e64b8ddacaf21381ffdefad57b1c3b3402a325","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["1ded679c5ad8b8ea375c402469b19aa10eda14eeafcea7513745efd2fc8cc18d","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"d3d0431a626178b450896aa9ee8cbb863f70f4da1213fb79f3dfd816907f8348","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"cm.light-induced-sc.k3c60-transient-state","kind":"phenomenon","literature_status":"contested","n":"2","parents":[],"plain":"After a mid-infrared pulse, the fulleride $\\mathrm{K_3C_{60}}$ shows an optical response like a superconductor at temperatures far above its normal $20\\ \\mathrm{K}$ transition, lasting up to nanoseconds. What state of matter this is remains unknown.","posed_since":"2016","precise":"$\\mathrm{K_3C_{60}}$ (equilibrium $T_{\\mathrm{c}} = 20\\,\\mathrm{K}$) excited at mid-infrared or terahertz frequencies shows a transient gap in $\\sigma_1(\\omega)$ and $\\sigma_2(\\omega) \\sim 1/\\omega$ well above $T_{\\mathrm{c}}$, with metastable states lasting nanoseconds at high fluence. Identify the state (transient superconductor, fluctuating pairs, high-mobility normal state, or analysis artifact) and its microscopic mechanism. Answer: a mechanism consistent with optical, transport and magnetic data.","problem_ref":"1ded679c5ad8b8ea375c402469b19aa10eda14eeafcea7513745efd2fc8cc18d","references":"","settled_by":"Transient magnetic, zero-resistance and optical measurements on the same samples, explained by one microscopic model.","status_note":"Dodge, Lopez and Sahota (arXiv:2307.00204, 2023) argue the optical evidence comes from an analysis flaw and reflects photoenhanced carrier mobility; a 2025 field-expulsion search (De Vecchi et al., arXiv:2502.20276) set only an upper limit.","title":"What is the photoexcited state of $\\mathrm{K_3C_{60}}$ above $T_{\\mathrm{c}}$?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5667ab628e15b0c59caac22466954f6409c60008a01440e1360dc6f29e1e99f9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"5cb3e6a62daf05cd105efb2cac6d56c24752905fd708d3347debea6c71234e81","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"dlfntCwmb4tJtfLLAbYOMpBc2U2MR9nNmz7eZx5NL_eVhH-8KmF_t0We9UTuRhKdjFotemcFXQwCuu6rmYtlDA"},"schema":"pubphys.envelope/1"},"record_hash":"5667ab628e15b0c59caac22466954f6409c60008a01440e1360dc6f29e1e99f9","leaf_index":2908}