{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b41ecd0690b4aa51ecc93acc7902adb12dbeda5d800e951c3874285148b59aed","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["8cf0de8f17c29b59dddd7826370dac399f75cd9e04c5813d16dfd0b6ef948ed3","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"fb3c2c937c2d7b0d4be3a83ddf07bb570260d495f96c7935c648ef558de0594b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"cm.magnetic-topological-insulators.qah-temperature","kind":"phenomenon","literature_status":"open","n":"2","parents":[],"plain":"Magnetic topological insulators show a perfectly quantized Hall resistance only at temperatures of order one kelvin, far below the temperature at which they become magnetic, and the reason is debated.","posed_since":"","precise":"In Cr- or V-doped (Bi,Sb)2Te3 films and odd-layer $\\mathrm{MnBi_2Te_4}$ flakes, full quantum anomalous Hall quantization ($R_{xy} = h/e^2, R_{xx} \\to 0$) appears only at $T$ of order 1 K, while magnetic order sets in at 10-30 K and spectroscopic exchange gaps of tens of meV are reported. Identify the mechanism limiting the quantization temperature (magnetic disorder and gap inhomogeneity, antisite defects, surface-gap fluctuations, parallel bulk conduction) and predict how to raise it. An answer quantitatively links measured disorder to the transport activation gap.","problem_ref":"8cf0de8f17c29b59dddd7826370dac399f75cd9e04c5813d16dfd0b6ef948ed3","references":"","settled_by":"Local imaging of the exchange gap correlated with transport activation energies across samples, reproducing the quantization temperature.","status_note":"","title":"Why zero-field quantized Hall effects survive only near one kelvin","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"93573223ec94f613070b577d17b4dacfa39349599c94ee858b4d9ab522802ccf","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"730e066f32e981eed76f77745b8342cf848c7e2c9e1a13842ad3ec06cd7a91d7","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"aT1SwQd_AqGNRpeYs8yqj2Zbjt0yhZOkVU8cO6wVzWpgknAWfWkIUWusibqcWQXXBWfkDTw-QVsts57aubVkCw"},"schema":"pubphys.envelope/1"},"record_hash":"93573223ec94f613070b577d17b4dacfa39349599c94ee858b4d9ab522802ccf","leaf_index":2922}