Artículos de revistas
Physical properties of the Schur complement of local covariance matrices
Registro en:
Journal Of Physics A-mathematical And Theoretical. Iop Publishing Ltd, v. 40, n. 47, n. 14195, n. 14205, 2007.
1751-8113
WOS:000250687800013
10.1088/1751-8113/40/47/011
Autor
Haruna, LF
de Oliveira, MC
Institución
Resumen
General properties of global covariance matrices representing bipartite Gaussian states can be decomposed into properties of local covariance matrices and their Schur complements. We demonstrate that given a bipartite Gaussian state rho(12) described by a 4 x 4 covariance matrix V, the Schur complement of a local covariance submatrix V-1 of it can be interpreted as a new covariance matrix representing a Gaussian operator of party 1 conditioned to local parity measurements on party 2. The connection with a partial parity measurement over a bipartite quantum state and the determination of the reduced Wigner function is given and an operational process of parity measurement is developed. Generalization of this procedure to an n-partite Gaussian state is given, and it is demonstrated that the n - 1 system state conditioned to a partial parity projection is given by a covariance matrix such that its 2 x 2 block elements are Schur complements of special local matrices. 40 47 14195 14205