Single-experiment-detectable nonclassical correlation witness

Abstract

Recent progress in theories of quantum information has determined nonclassical correlation defined differently from widely-used entanglement as an important property to evaluate computation and communication with mixed quantum states. We introduce an operational method to detect nonclassical correlation of bipartite systems. In this method, we use particular maps analogous to the well-established entanglement witnesses. Thus, the maps are called nonclassical correlation witness maps. Furthermore, it is proved that such a map can be generally decomposed so that a single-run experiment is feasible for implementation in bulk-ensemble systems.Comment: 5 pages, 1 figure; v2: minor revisions, also an analytical proof has been added; v3: to appear in Phys. Rev. A, a theorem adde

Pseudo-entanglement evaluated in noninertial frames

“…This behavior is not observed for quantum discord explained below. As for nonclassical correlations, among the exiting measures [18,29,31,34,35,36,37,38,39,40], we evaluate quantum discord [18], which has been studied for quantum computing [21,37,41,42] and broadcasting of quantum states [43,44]. The dynamics of quantum discord is also studied [45].…”

Characterization of correlations in two-fermion systems based on measurement induced disturbances

“…Indeed, as was established in a pioneering work by Zurek and Ollivier [17], even separable mixed states can be endowed with correlations exhibiting non-trivial quantum features. In the case of systems consisting of distinguishable parts various measures have been advanced to characterize quantitatively the different ways (besides entanglement) in which quantum correlations can manifest themselves [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Prominent among these are quantum discord and the measures of correlations based upon the disturbances of quantum states due to local measurements proposed by Luo [21][22][23] and by SaiToh and collaborators [28,29].…”

Asymptotic dynamics of quantum discord in open quantum systems

“…Recently various methods to detect zero-discord [28][29][30] have been proposed for a given state as well as for an unknown state [31]. Moreover, it is found that vanishing quantum discord is related to the complete positivity of a map [32] and the local broadcasting of quantum correlations [15].…”