Artículos de revistas
Quantum Discord for d circle times 2 Systems
Fecha
2015-06-03Registro en:
Scientific Reports. London: Nature Publishing Group, v. 5, p. 1-7, 2015.
2045-2322
10.1038/srep10262
WOS:000355647900001
WOS000355647900001.pdf
8884890472193474
0000-0003-3297-905X
Autor
Shanghai Jiao Tong Univ
UCL
Zhejiang Univ Technol
Natl Univ Singapore
Universidade Estadual Paulista (Unesp)
Capital Normal Univ
Max Planck Inst Math Sci
Institución
Resumen
We present an analytical solution for classical correlation, defined in terms of linear entropy, in an arbitrary d circle times 2 system when the second subsystem is measured. We show that the optimal measurements used in the maximization of the classical correlation in terms of linear entropy, when used to calculate the quantum discord in terms of von Neumann entropy, result in a tight upper bound for arbitrary d circle times 2 systems. This bound agrees with all known analytical results about quantum discord in terms of von Neumann entropy and, when comparing it with the numerical results for 10(6) two-qubit random density matrices, we obtain an average deviation of order 10(-4). Furthermore, our results give a way to calculate the quantum discord for arbitrary n-qubit GHZ and W states evolving under the action of the amplitude damping noisy channel.