Physics – Quantum Physics
Scientific paper
1999-08-24
Physics
Quantum Physics
13 pages including 3 PostScript figures. v3 has updated references and discussion, to appear Phys. Rev. A
Scientific paper
In an effort to simplify the classification of pure entangled states of multi (m) -partite quantum systems, we study exactly and asymptotically (in n) reversible transformations among n'th tensor powers of such states (ie n copies of the state shared among the same m parties) under local quantum operations and classical communication (LOCC). With regard to exact transformations, we show that two states whose 1-party entropies agree are either locally-unitarily (LU) equivalent or else LOCC-incomparable. In particular we show that two tripartite Greenberger-Horne-Zeilinger (GHZ) states are LOCC-incomparable to three bipartite Einstein-Podolsky-Rosen (EPR) states symmetrically shared among the three parties. Asymptotic transformations result in a simpler classification than exact transformations. We show that m-partite pure states having an m-way Schmidt decomposition are simply parameterizable, with the partial entropy across any nontrivial partition representing the number of standard ``Cat'' states (|0^m>+|1^m>) asymptotically interconvertible to the state in question. For general m-partite states, partial entropies across different partitions need not be equal, and since partial entropies are conserved by asymptotically reversible LOCC operations, a multicomponent entanglement measure is needed, with each scalar component representing a different kind of entanglement, not asymptotically interconvertible to the other kinds. In particular the m=4 Cat state is not isentropic to, and therefore not asymptotically interconvertible to, any combination of bipartite and tripartite states shared among the four parties. Thus, although the m=4 cat state can be prepared from bipartite EPR states, the preparation process is necessarily irreversible, and remains so even asymptotically.
Bennett Charles H.
Popescu Sandu
Rohrlich Daniel
Smolin John A.
Thapliyal Ashish V.
No associations
LandOfFree
Exact and Asymptotic Measures of Multipartite Pure State Entanglement does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Exact and Asymptotic Measures of Multipartite Pure State Entanglement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exact and Asymptotic Measures of Multipartite Pure State Entanglement will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-677276