Artículos de revistas
Sudden change of quantum discord for a system of two qubits
Fecha
2013-09-30Registro en:
Physical Review A - Atomic, Molecular, and Optical Physics, v. 88, n. 3, 2013.
1050-2947
1094-1622
10.1103/PhysRevA.88.034304
WOS:000325161700025
2-s2.0-84885360606
2-s2.0-84885360606.pdf
8884890472193474
0000-0003-3297-905X
Autor
Universidade Federal de Ouro Preto (UFOP)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
It is known that quantum discord might experience a sudden transition in its dynamics when calculated for certain Bell-diagonal states (BDS) that are in interaction with their surroundings. We examine this phenomenon, known as the sudden change of quantum discord, considering the case of two qubits independently interacting with dephasing reservoirs. We first demonstrate that, for a class of initial states which can be chosen arbitrarily close to BDS, the transition is in fact not sudden, although it might numerically appear so if not studied carefully. Then, we provide an extension of this discussion covering the X-shaped density matrices. Our findings suggest that the transition of quantum discord might be sudden only for an highly idealized zero-measure subset of states within the set of all possible initial conditions of two qubits. © 2013 American Physical Society.