{ "id": "quant-ph/0605079", "version": "v1", "published": "2006-05-08T17:25:55.000Z", "updated": "2006-05-08T17:25:55.000Z", "title": "Geometrical aspects of entanglement", "authors": [ "Jon Magne Leinaas", "Jan Myrheim", "Eirik Ovrum" ], "comment": "31 pages, 6 figures", "doi": "10.1103/PhysRevA.74.012313", "categories": [ "quant-ph" ], "abstract": "We study geometrical aspects of entanglement, with the Hilbert--Schmidt norm defining the metric on the set of density matrices. We focus first on the simplest case of two two-level systems and show that a ``relativistic'' formulation leads to a complete analysis of the question of separability. Our approach is based on Schmidt decomposition of density matrices for a composite system and non-unitary transformations to a standard form. The positivity of the density matrices is crucial for the method to work. A similar approach works to some extent in higher dimensions, but is a less powerful tool. We further present a numerical method for examining separability, and illustrate the method by a numerical study of bound entanglement in a composite system of two three-level systems.", "revisions": [ { "version": "v1", "updated": "2006-05-08T17:25:55.000Z" } ], "analyses": { "keywords": [ "density matrices", "composite system", "similar approach works", "study geometrical aspects", "bound entanglement" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. A" }, "note": { "typesetting": "TeX", "pages": 31, "language": "en", "license": "arXiv", "status": "editable" } } }