Quantum correlation provides a promising measure beyond entanglement. Here, we propose a necessary and sufficient condition for nonzero quantum correlation in continuous variable systems, which is simple and easy to perform in terms of a marker Q r . In order to get this condition, we introduce continuous-variable local orthogonal bases of the operator space, which are generalized from the orthogonal basis sets in local operator space for discrete variables. Based on this, we obtain the marker Q r for all bipartite continuous variable states, and provide several examples including two-mode Gaussian and non-Gaussian states. Our result may provide a candidate for quantum correlation measures, and can be measured by designed quantum circuits.Quantum correlation provides a promising measure beyond entanglement. Here, we propose a necessary and sufficient condition for nonzero quantum correlation in continuous variable systems, which is simple and easy to perform in terms of a marker Q r . In order to get this condition, we introduce continuous-variable local orthogonal bases of the operator space, which are generalized from the orthogonal basis sets in local operator space for discrete variables. Based on this, we obtain the marker Q r for all bipartite continuous variable states, and provide several examples including two-mode Gaussian and non-Gaussian states. Our result may provide a candidate for quantum correlation measures, and can be measured by designed quantum circuits.

arXiv:1308.4810New Journal of PhysicsSep 10, 20151 citation

Generalized Quantum Correlations in Discrete Variable Systems

Farid Shähandeh

Springer thesesJan 1, 20192 citations

Necessary and sufficient condition for nonzero quantum discord in continuous variable systems

Chengjie Zhang, Sixia Yu, Qing Chen +2 more

Quantum discord provides a promising measure for the quantum correlation beyond entanglement, and may be responsible for the quantum speedup in certain quantum computing tasks. Here, we propose a necessary and sufficient condition for nonzero quantum discord in continuous variable systems, which is simple and easy to perform in terms of a marker $Q$ . In order to obtain this condition, we introduce the continuous-variable local orthogonal basis of the operator space generalized from the orthogonal basis sets in local operator space for discrete variables. Based on this, we derive an explicit expression of the marker $Q$ for all the two-mode states, and present examples of all Gaussian states and several non-Gaussian states. Our result provides a candidate for quantum correlation measures, and can be easily measured by a designed quantum circuit.Quantum discord provides a promising measure for the quantum correlation beyond entanglement, and may be responsible for the quantum speedup in certain quantum computing tasks. Here, we propose a necessary and sufficient condition for nonzero quantum discord in continuous variable systems, which is simple and easy to perform in terms of a marker $Q$. In order to obtain this condition, we introduce the continuous-variable local orthogonal basis of the operator space generalized from the orthogonal basis sets in local operator space for discrete variables. Based on this, we derive an explicit expression of the marker $Q$ for all the two-mode states, and present examples of all Gaussian states and several non-Gaussian states. Our result provides a candidate for quantum correlation measures, and can be easily measured by a designed quantum circuit.

Aug 22, 20130 citations

Q

. In order to obtain this condition, we introduce the continuous-variable local orthogonal basis of the operator space generalized from the orthogonal basis sets in local operator space for discrete variables. Based on this, we derive an explicit expression of the marker

Q

for all the two-mode states, and present examples of all Gaussian states and several non-Gaussian states. Our result provides a candidate for quantum correlation measures, and can be easily measured by a designed quantum circuit.