{ "id": "1110.5944", "version": "v2", "published": "2011-10-26T23:09:03.000Z", "updated": "2011-12-23T01:21:19.000Z", "title": "Communication cost of classically simulating a quantum channel with subsequent rank-1 projective measurement", "authors": [ "Alberto Montina" ], "comment": "corrected some minor typos", "journal": "Phys. Rev. A 84, 060303(R) (2011)", "doi": "10.1103/PhysRevA.84.060303", "categories": [ "quant-ph", "cs.IT", "math-ph", "math.IT", "math.MP" ], "abstract": "A process of preparation, transmission and subsequent projective measurement of a qubit can be simulated by a classical model with only two bits of communication and some amount of shared randomness. However no model for n qubits with a finite amount of classical communication is known at present. A lower bound for the communication cost can provide useful hints for a generalization. It is known for example that the amount of communication must be greater than c 2^n, where c~0.01. The proof uses a quite elaborate theorem of communication complexity. Using a mathematical conjecture known as the \"double cap conjecture\", we strengthen this result by presenting a geometrical and extremely simple derivation of the lower bound 2^n-1. Only rank-1 projective measurements are involved in the derivation.", "revisions": [ { "version": "v2", "updated": "2011-12-23T01:21:19.000Z" } ], "analyses": { "subjects": [ "03.67.Hk", "03.67.Lx" ], "keywords": [ "communication cost", "quantum channel", "classically simulating", "lower bound", "quite elaborate theorem" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Physical Review A", "year": 2011, "month": "Dec", "volume": 84, "number": 6, "pages": "060303" }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011PhRvA..84f0303M" } } }