{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b348569a6128d8bceb8b646c9ae97cf8abe866d4ecd8cf6205331db12ceb18b4","created":"2026-10-03T07:18:00Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"481eb14cf3bc7f1c676cfbad9befa6726539f52f0a25791867ee0ce25db36d21","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":"1","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 MnBi2Te4 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":null,"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":"eef15c72032faa1168fa9014695d510856a871a88df07cd67b817c3027aab793"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8cf0de8f17c29b59dddd7826370dac399f75cd9e04c5813d16dfd0b6ef948ed3","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3fe1da4ec54594e184a7f609caf9d0060111ebcc46d6b872269dba2894f3c66f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"1ADTGowxAOiXrj2nmAnb9Wr0Ru8EMGremVmyKj5wYmqXWVceyCSkgg3PNAkmWXsYdNWs3iJeR9JkNBUgfvE5Bw"},"schema":"pubphys.envelope/1"},"record_hash":"8cf0de8f17c29b59dddd7826370dac399f75cd9e04c5813d16dfd0b6ef948ed3","leaf_index":1076}