{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2b141eb5654fc49ef5c306eeab164f619c9d13af99a5902e6aeeaa6fd55752b7","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"07f9012e00db1f65cea2326d4b2808a95635f97e43e616ee0be56b54109b418e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"cm.moire-graphene-superconductivity.pairing-mechanism","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"Superconductivity needs electrons to pair up despite repelling each other, and in magic-angle graphene it is unknown whether lattice vibrations (phonons) or the electrons' own interactions supply the attraction.","posed_since":"2018","precise":"Twisted bilayer graphene at $\\theta \\sim 1.05-1.15\\,\\mathrm{deg}$ superconducts with $T_c$ up to $\\sim 3\\,\\mathrm{K}$ near filling $\\nu = -2 - \\delta$ ($\\nu$ = electrons per moire cell measured from charge neutrality). Determine the dominant pairing interaction (intervalley K-point optical phonons, other phonons, spin or valley fluctuations, Coulomb-driven Kohn-Luttinger pairing, or a combination) and the order-parameter symmetry. An answer is a microscopic model that reproduces the measured $T_c(\\nu, \\theta)$, tunnelling gap spectrum and superfluid stiffness without retuned parameters.","problem_ref":null,"references":"","settled_by":"A phase-sensitive gap-symmetry measurement plus an isotope or phonon-engineering test, combined with a parameter-free calculation reproducing $T_{c}(\\nu, \\theta)$.","status_note":"2024 photoemission (Chen et al., Nature 636, 342) found flat-band replicas from strong coupling to a $\\sim 150\\,\\mathrm{meV}$ K-point phonon, while 2025 superfluid-stiffness data show power-law temperature dependence pointing to unconventional pairing; no consensus as of 2026.","title":"What binds electron pairs in magic-angle graphene superconductors","topic_ref":"772455301d33c1cea6c0cbed25bb79fa87ea5b401f9a667e1c0b4056e25a3e52"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"4e26afc00b7011defe0fb8dd7e4edec02af962c3bb628d77fb25bedb149ad4e3","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"b3147757e5eefa19f51fe58441bf459c7d4f424b4f015a6bb9f744cdc43eb669","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"94EAah8unhMXJo3dYiOPacL-NaqX6WQuUgqKunVx7TqfGFOn8zYRlPdeP6wsVMLSuYNCV3dm5eYVCg-ohcqOCg"},"schema":"pubphys.envelope/1"},"record_hash":"4e26afc00b7011defe0fb8dd7e4edec02af962c3bb628d77fb25bedb149ad4e3","leaf_index":1095}