{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"148062bb50efa1475afa574c216efd5f4ad5b51d95fdff6a2de6fbdc12801400","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["59f957c2f40101b3fca46514da459caf14ef7a6e349db17b552d926ed0a84016","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"2cd107b51f61b6a165b5a598c7f6712b08b2f8662a49e768486b71ede727cf04","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.multiferroics.monolayer-type-ii","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"Type-II multiferroics are materials whose spiral spin order itself creates electric polarization. A single atomic layer of $\\mathrm{NiI_2}$ has been shown to host the spin spiral, but its electric polarization has not been measured directly.","posed_since":"2022","precise":"Single-layer $\\mathrm{NiI_2}$ shows a canted spin spiral with charge modulation in spin-polarized STM. Measure the spin-induced polarization $P$ and its onset temperature $T_{c}$ directly, by electrical (pyroelectric or switching current) or piezoresponse probes, and test whether $P$ reverses with the spiral chirality. An answer is the measured $P(T)$ and $T_{c}$ with the chirality dependence.","problem_ref":"59f957c2f40101b3fca46514da459caf14ef7a6e349db17b552d926ed0a84016","references":"","settled_by":"Pyroelectric, switching-current or piezoresponse measurement of P(T) on a characterized monolayer, combined with spin-polarized STM of its spiral chirality.","status_note":"Song et al. (Nature 2022) was questioned by Jiang et al. (Nature 2023, Matters Arising); STM detected electromagnons (arXiv:2510.08253) and vectorial spin-polarized STM resolved the spiral (Wang et al., PRL 2026, arXiv:2604.06959); no direct electrical measurement of P in the monolayer was found.","title":"Direct electrical measurement of polarization in monolayer $\\mathrm{NiI_2}$","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b79250ea466d6d6cfbe6c99972c943e5c6b7ef2f1fc2c41eef0d54df7962cf21","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"04601a67075d035bbd336220de059b208e9b0bec213d3d22ded46a75f8b515e5","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"WDvVgkpWBrAwtzTioWhzJGFiWQgCYa7DhJ0SNPRA1Yy7TF6lTtQPRKu0gZQYB5Zeknv5JdW7_XjMUaV461M8Ag"},"schema":"pubphys.envelope/1"},"record_hash":"b79250ea466d6d6cfbe6c99972c943e5c6b7ef2f1fc2c41eef0d54df7962cf21","leaf_index":2958}