{"paper":{"title":"Nodal Topological Superconductivity Driven by Crystalline Antiunitary Symmetry in Altermagnets","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Crystalline antiunitary symmetry in fourfold altermagnets forbids pure spin-singlet pairing and selects structures yielding emergent chiral symmetries that produce nodal topological superconductivity.","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"Arun Bansil, Xiao Xiao","submitted_at":"2026-05-13T15:14:50Z","abstract_excerpt":"Topological superconductivity hosts protected quasiparticles and is central to topological quantum computation, yet its realization in intrinsic materials remains challenging and often relies on engineered platforms. Here we uncover a symmetry-constrained mechanism for nodal topological superconductivity in altermagnets. Focusing on fourfold rotational collinear altermagnets, we show that the native crystalline antiunitary symmetry $\\mathcal{T}C_{4z}$ generically forbids pure spin-singlet pairing and selects pairing structures that admit Bogoliubov-de Gennes (BdG) Hamiltonians with emergent ch"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"the native crystalline antiunitary symmetry T C4z generically forbids pure spin-singlet pairing and selects pairing structures that admit Bogoliubov-de Gennes (BdG) Hamiltonians with emergent chiral symmetries. These symmetries further give rise to robust nodal topological phases over broad parameter regimes, including a nodal-point phase hosting Majorana flat bands (MFBs) and two distinct nodal-loop phases with chiral Majorana edge states.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the dominant pairing interaction in real fourfold altermagnets falls into the symmetry-selected channels that produce the emergent chiral symmetries, without being overwhelmed by competing orders or other pairing symmetries.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Crystalline antiunitary symmetry in altermagnets selects pairing that produces robust nodal topological superconducting phases with Majorana flat bands and chiral edge states.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Crystalline antiunitary symmetry in fourfold altermagnets forbids pure spin-singlet pairing and selects structures yielding emergent chiral symmetries that produce nodal topological superconductivity.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"cd9da0fbfdbdde4fc5d1c5fe8927be17f185f75bef986a3d0c60cb829b67906f"},"source":{"id":"2605.13656","kind":"arxiv","version":1},"verdict":{"id":"b20e9539-ef0f-4046-a851-3be3d3f55e58","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T18:09:55.440212Z","strongest_claim":"the native crystalline antiunitary symmetry T C4z generically forbids pure spin-singlet pairing and selects pairing structures that admit Bogoliubov-de Gennes (BdG) Hamiltonians with emergent chiral symmetries. These symmetries further give rise to robust nodal topological phases over broad parameter regimes, including a nodal-point phase hosting Majorana flat bands (MFBs) and two distinct nodal-loop phases with chiral Majorana edge states.","one_line_summary":"Crystalline antiunitary symmetry in altermagnets selects pairing that produces robust nodal topological superconducting phases with Majorana flat bands and chiral edge states.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the dominant pairing interaction in real fourfold altermagnets falls into the symmetry-selected channels that produce the emergent chiral symmetries, without being overwhelmed by competing orders or other pairing symmetries.","pith_extraction_headline":"Crystalline antiunitary symmetry in fourfold altermagnets forbids pure spin-singlet pairing and selects structures yielding emergent chiral symmetries that produce nodal topological superconductivity."},"references":{"count":88,"sample":[{"doi":"","year":1991,"title":"M. Sigrist and K. Ueda, Phenomenological theory of un- conventional superconductivity, Rev. Mod. Phys.63, 239 (1991)","work_id":"a5c14532-89c0-496d-8e61-ec20f55882b9","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1999,"title":"V. P. Mineev and K. V. Samokhin,Introduction to Un- conventional Superconductivity(Gordon and Breach Sci- ence Publishers, Amsterdam, 1999)","work_id":"5f36c093-8841-4943-9536-48d424c92351","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2017,"title":"M. Sato and Y. Ando, Topological superconductors: a re- view, Reports on Progress in Physics80, 076501 (2017)","work_id":"88598684-9bb4-4896-8246-f431405f8846","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2012,"title":"Alicea, New directions in the pursuit of majorana fermions in solid state systems, Reports on Progress in Physics75, 076501 (2012)","work_id":"972f9436-0e19-44cb-ab97-ad87bb8fbe98","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2017,"title":"F. Pientka, A. Keselman, E. Berg, A. Yacoby, A. Stern, and B. I. Halperin, Topological superconductivity in a planar josephson junction, Phys. Rev. X7, 021032 (2017)","work_id":"caf50074-d961-4a69-9d1d-82b2d7a4e704","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":88,"snapshot_sha256":"694140fa71cf26de648f74d1f147207578c37bd448c23e7bc9ec843b668907a7","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"3cdf8591271dd0e15fd25474fbecf0045e373e1e8cebf2ddcd023a71ee4e0232"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}