{ "id": "quant-ph/0108076", "version": "v2", "published": "2001-08-16T16:52:34.000Z", "updated": "2002-05-20T16:51:33.000Z", "title": "Optimal simulation of nonlocal Hamiltonians using local operations and classical communication", "authors": [ "G. Vidal", "J. I. Cirac" ], "comment": "10 pages, 1 figure, revtex, major changes in presentation, results unchanged", "journal": "Phys. Rev. A 66, 022315 (2002)", "doi": "10.1103/PhysRevA.66.022315", "categories": [ "quant-ph" ], "abstract": "Consider a set of $N$ systems and an arbitrary interaction Hamiltonian $H$ that couples them. We investigate the use of local operations and classical communication (LOCC), together with the Hamiltonian $H$, to simulate a unitary evolution of the $N$ systems according to some other Hamiltonian $H'$. First, we show that the most general simulation using $H$ and LOCC can be also achieved, with the same time efficiency, by just interspersing the evolution of $H$ with local unitary manipulations of each system and a corresponding local ancilla (in a so-called LU+anc protocol). Thus, the ability to make local measurements and to communicate classical information does not help in non--local Hamiltonian simulation. Second, we show that both for the case of two $d$-level systems ($d>2$), or for that of a setting with more than two systems ($N>2$), LU+anc protocols are more powerful than LU protocols. Therefore local ancillas are a useful resource for non--local Hamiltonian simulation. Third, we use results of majorization theory to explicitly solve the problem of optimal simulation of two-qubit Hamiltonians using LU (equivalently, LU+anc, LO or LOCC).", "revisions": [ { "version": "v2", "updated": "2002-05-20T16:51:33.000Z" } ], "analyses": { "keywords": [ "local operations", "optimal simulation", "classical communication", "nonlocal hamiltonians", "non-local hamiltonian simulation" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. A" }, "note": { "typesetting": "RevTeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }