{ "id": "2404.07633", "version": "v1", "published": "2024-04-11T10:52:04.000Z", "updated": "2024-04-11T10:52:04.000Z", "title": "One-dimensional $\\mathbb{Z}_4$ topological superconductor", "authors": [ "Max Tymczyszyn", "Edward McCann" ], "comment": "7 pages, 5 figures, plus supplementary 12 pages", "categories": [ "cond-mat.mes-hall", "cond-mat.supr-con" ], "abstract": "We describe the mean-field model of a one-dimensional topological superconductor with two orbitals per unit cell. Time-reversal symmetry is absent, but a nonsymmorphic symmetry, involving a translation by a fraction of the unit cell, mimics the role of time-reversal symmetry. As a result, the topological superconductor has $\\mathbb{Z}_4$ topological phases, two which support Majorana bound states and two which do not, in agreement with a prediction based on K-theory classification [K. Shiozaki et al., Phys. Rev. B 93, 195413 (2016)]. As with the Kitaev chain, the presence of Majorana bound states gives rise to the $4\\pi$-periodic Josephson effect. The K-theory classification describes two $\\mathbb{Z}_4$ subclasses, but, by identifying models in both subclasses, we show that they are related by a unitary transformation and are equivalent.", "revisions": [ { "version": "v1", "updated": "2024-04-11T10:52:04.000Z" } ], "analyses": { "keywords": [ "time-reversal symmetry", "support majorana bound states", "unit cell", "k-theory classification", "periodic josephson effect" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }