{ "id": "2104.11581", "version": "v1", "published": "2021-04-23T13:30:05.000Z", "updated": "2021-04-23T13:30:05.000Z", "title": "Entanglement of Free Fermions on Johnson Graphs", "authors": [ "Pierre-Antoine Bernard", "Nicolas Crampe", "Luc Vinet" ], "comment": "24 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "Free fermions on Johnson graphs $J(n,k)$ are considered and the entanglement entropy of sets of neighborhoods is computed. For a subsystem composed of a single neighborhood, an analytical expression is provided by the decomposition in irreducible submodules of the Terwilliger algebra of $J(n,k)$ embedded in two copies of $\\mathfrak{su}(2)$. For a subsytem composed of multiple neighborhoods, the construction of a block-tridiagonal operator which commutes with the entanglement Hamiltonian is presented, its usefulness in computing the entropy is stressed and the area law pre-factor is discussed.", "revisions": [ { "version": "v1", "updated": "2021-04-23T13:30:05.000Z" } ], "analyses": { "keywords": [ "free fermions", "johnson graphs", "area law pre-factor", "terwilliger algebra", "single neighborhood" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }