2017/05/24 by Y. B. Band, Pier A. Mello, Band, Yehuda B. +1
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.1705.09613
openalex publication_date 2017/05/24 · openalex created_date 2022/08/13 · openalex updated_date 2026/07/28
We show that partial transposition for pure and mixed two-particle states in\na discrete N-dimensional Hilbert space is equivalent to a change in sign of a\n"momentum-like" variable of one of the particles in the Wigner function for the\nstate. This generalizes a result obtained for continuous-variable systems to\nthe discrete-variable system case. We show that, in principle, quantum\nmechanics allows measuring the expectation value of an observable in a\npartially transposed state, in spite of the fact that the latter may not be a\nphysical state. We illustrate this result with the example of an "isotropic\nstate", which is dependent on a parameter r, and an operator whose variance\nbecomes negative for the partially transposed state for certain values of r;\nfor such r, the original states are entangled.\n