{ "id": "1503.05342", "version": "v1", "published": "2015-03-18T11:08:07.000Z", "updated": "2015-03-18T11:08:07.000Z", "title": "Beyond Complete Positivity", "authors": [ "Jason M. Dominy", "Daniel A. Lidar" ], "comment": "9 pages, 1 figure", "categories": [ "quant-ph", "math-ph", "math.MP" ], "abstract": "We provide a general and consistent formulation for linear subsystem quantum dynamical maps, developed from a minimal set of postulates, primary among which is a relaxation of the usual, restrictive assumption of uncorrelated initial system-bath states. We describe the space of possibilities admitted by this formulation, namely that, far from being limited to only completely positive (CP) maps, essentially any C-linear, Hermiticity- preserving, trace-preserving subsystem map can arise as a legitimate subsystem dynamical map from a joint unitary evolution of a system coupled to a bath. The price paid for this added generality is a trade-off between the set of admissible initial states and the allowed set of joint system-bath unitary evolutions. As an application we present a simple example of a non-CP map constructed as a subsystem dynamical map that violates some fundamental inequalities in quantum information theory, such as the quantum data processing inequality.", "revisions": [ { "version": "v1", "updated": "2015-03-18T11:08:07.000Z" } ], "analyses": { "keywords": [ "complete positivity", "linear subsystem quantum dynamical maps", "joint system-bath unitary evolutions", "joint unitary evolution", "quantum data processing inequality" ], "publication": { "doi": "10.1007/s11128-015-1228-1", "journal": "Quantum Information Processing", "year": 2016, "month": "Apr", "volume": 15, "number": 4, "pages": 1349 }, "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016QuIP...15.1349D" } } }