{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c8020e5458e8e5b617a185f87cb633d54b405b3d176773725c856a33271cd8d3","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5be4755edd3b1b836dd23e6509a783007913ac591e3e966ecae604a0bc82197e","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"79394ca48600e2c3fa9f32a5f63c26b7ded6a0549abf5282d929c89918697f50","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"cm.majorana-zero-modes.shiba-chains","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"Chains of iron atoms on superconducting lead show zero-energy states at their ends that were proposed as Majorana modes, but ordinary bound states can look similar, and the identification is unsettled.","posed_since":"2014","precise":"STM on Fe atomic chains on Pb(110) (Nadj-Perge et al., Science 346, 602, 2014, doi:10.1126/science.1259327) and on later chains assembled atom by atom on superconductors shows zero-bias features at chain ends. Determine whether these are Majorana zero modes of a topological band of hybridized Yu-Shiba-Rusinov states (bound states induced by magnetic atoms in a superconductor). Required: a resolved bulk topological gap larger than the end-mode splitting, splitting that decays exponentially with chain length, and zero-bias conductance $2e^{2}/h$ in the strong-coupling tunnelling limit. An answer is yes or no for a specified chain system.","problem_ref":"5be4755edd3b1b836dd23e6509a783007913ac591e3e966ecae604a0bc82197e","references":"","settled_by":"Length-dependent spectroscopy on atom-by-atom assembled chains showing exponential decay of end-mode splitting with a resolved topological gap.","status_note":"Trivial interpretations of the end states are not excluded as of 2026, to this survey's knowledge.","title":"Are end states of magnetic atom chains on superconductors Majorana modes?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"082489f9f6e5e06d379f5cb3959a1585f3d39875969d6af9060f52ca444afbcc","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"f74882217713c67a5f30317d787556c3a6fc9fe7417737f87ecbf7ea5e83bfd3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Jy0ZdCrkQ4CrBxp2uLu2Zw5t7lnIbPT5D-jIch3xL68t_IQgwtHBF9m-L6_5qY-QA4u6cXrkaIhRQTKwS0elCg"},"schema":"pubphys.envelope/1"},"record_hash":"082489f9f6e5e06d379f5cb3959a1585f3d39875969d6af9060f52ca444afbcc","leaf_index":2928}