{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"48b28af2706cef8d08d6bda3d3ab97c3e07a430bd15ec04613bf8ac2f639c493","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["9b5ebb42650f9d2a33dcb48b0463da5fbc22f264fa9f60e3ca4407cb55d26a5e","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"fe30b70ff6b9375b5497c79f6432f502df520e2a6ac47c3c87fe93ec7f33250b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"cm.altermagnets.all-altermagnet-tmr","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Theory predicts that a tunnel junction made only of altermagnets should change its resistance strongly when one electrode's spin pattern is reversed, giving a memory bit without ferromagnets. No experiment has yet shown this in a junction built only from altermagnets.","posed_since":"2022","precise":"In an altermagnet/insulator/altermagnet junction (candidates CrSb, Cr-doped $\\mathrm{RuO_2}$, $\\mathrm{KV_2Se_2O}$, MnTe) with no ferromagnetic layer, measure $\\mathrm{TMR}=(R_{\\mathrm{AP}}-R_{\\mathrm{P}})/R_{\\mathrm{P}}$ at $T=300\\,\\mathrm{K}$, where P and AP denote parallel and antiparallel Neel vectors, and determine whether it exceeds 100 percent as nonrelativistic spin-splitting theory predicts. An answer is the measured TMR with device structure and evidence that it arises from the altermagnetic band splitting.","problem_ref":"9b5ebb42650f9d2a33dcb48b0463da5fbc22f264fa9f60e3ca4407cb55d26a5e","references":"","settled_by":"Epitaxial all-altermagnet junctions with controlled Neel-vector switching and room-temperature TMR measurements.","status_note":"Work found for 2025-2026 is theoretical: a CrSb-based junction proposal (arXiv:2503.13850) and a first-principles all-altermagnet Cr-doped $\\mathrm{RuO_2}$/$\\mathrm{TiO_2}$/Cr-doped $\\mathrm{RuO_2}$ junction (arXiv:2607.21092); no experimental all-altermagnet junction with TMR above 100 percent at 300 K was found.","title":"Large tunneling magnetoresistance in all-altermagnetic tunnel junctions","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8222afa6c975cb069ad8a8fdd0c30c9fefb580191af8665e47dd1a56960f8f56","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e5dcea85e33294b3f82f588307d65de182a230e4ae95fdd57a3f257fc1bd5a17","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"aPdsSTu9fTdaYFtjyNaZ6nmr8Z_e4DtYMyUe6DdjosIExQ9zZoEhLjNnYLMuwsagVsCvel3ExMeEqEg_qqePCQ"},"schema":"pubphys.envelope/1"},"record_hash":"8222afa6c975cb069ad8a8fdd0c30c9fefb580191af8665e47dd1a56960f8f56","leaf_index":2690}