Phys. Rev. Lett. 100, 050501 (2008) [4 pages]Only n-Qubit Greenberger-Horne-Zeilinger States Are Undetermined by Their Reduced Density MatricesReceived 1 August 2007; revised 22 October 2007; published 4 February 2008 The generalized n-qubit Greenberger-Horne-Zeilinger (GHZ) states and their local unitary equivalents are the only states of n qubits that are not uniquely determined among pure states by their reduced density matrices of n-1 qubits. Thus, among pure states, the generalized GHZ states are the only ones containing information at the n-party level. We point out a connection between local unitary stabilizer subgroups and the property of being determined by reduced density matrices. © 2008 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.100.050501
DOI:
10.1103/PhysRevLett.100.050501
PACS:
03.67.Mn, 03.65.Ta, 03.65.Ud
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.