{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"5515a4ded4d11d7da30318f3ac3762b625d5bb8c244e778e9d8062a822b2f57f","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["b1b88f2951011c1f6ea359f504e641fbd33fae0b261707a1d1a80014b91a74f5","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"72a90720f565436e35b39df520fe387e1f005deb8602f66bbbcfc78ce8f65763","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"cm.helium3-quantum-solids.2d-3he-spin-liquid","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"A layer of helium-3 atoms adsorbed on graphite forms a triangular solid in which nuclear spins interact through atoms exchanging places in rings. Down to the lowest temperatures reached, these spins show no order, suggesting a quantum spin liquid.","posed_since":"","precise":"At the $4/7$ commensurate density of the 2D solid 3He layer on preplated graphite, multiple-spin ring exchange on a triangular lattice produces no magnetic order: magnetization measured by direct nuclear demagnetization rises smoothly down to about $10^{-5}\\,\\mathrm{K}$, which bounds any spin gap below about $10^{-5}\\,\\mathrm{K}$ (Masutomi et al. 2004). Determine the ground state of the triangular ring-exchange model at the measured $J2, J4, J5, J6$ ratios and test experimentally whether the state is a gapless spin liquid, gapped, or ordered. An answer is a classification supported by both computation and data below $10^{-5}\\,\\mathrm{K}$.","problem_ref":"b1b88f2951011c1f6ea359f504e641fbd33fae0b261707a1d1a80014b91a74f5","references":"","settled_by":"Heat capacity and susceptibility below $10^{-5}$ K together with a controlled numerical solution of the ring-exchange model at the measured couplings.","status_note":"","title":"Is second-layer 3He on graphite a gapless spin liquid?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"31d7123b3f9c9af6a55824b83c54b024d9eac0c4979ffb778aa50c376ee2e428","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c846ae272868d20aa6cf29d8c19a8200bac4deabb99c59f2cde39733b0884b62","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"ZBaATSIZ1XTjFoYZlifMSN32yUBuBGVuKz7mYcKuapzybHMIkar2KQjPWYDsOzljARrFtLHkIl-LR_t88-1EBA"},"schema":"pubphys.envelope/1"},"record_hash":"31d7123b3f9c9af6a55824b83c54b024d9eac0c4979ffb778aa50c376ee2e428","leaf_index":2848}