Quantum discord for two-qubit X states
By Mazhar N. Ali, A. Rau, G. Alber. 2010
831 citations recorded by the source corpus.
Quantum discord, a kind of quantum correlation, is defined as the difference between quantum mutual information and classical correlation in a bipartite system. In general, this correlation is different from entanglement, and quantum discord may be nonzero even for certain separable states. Even in the simple case of bipartite quantum systems, this different kind of quantum correlation has interesting and significant applications in quantum information processing. So far, quantum discord has been calculated explicitly only for a rather limited set of two-qubit quantum states and expressions for more general quantum states are not known. In this article, we derive explicit expressions for quantum discord for a larger class of two-qubit states, namely, a seven-parameter family of so called X states that have been of interest in a variety of contexts in the field. We also study the relation between quantum discord, classical correlation, and entanglement for a number of two-qubit states to demonstrate that they are independent measures of correlation with no simple relative ordering between them.
Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics
View Paper: https://www.semanticscholar.org/paper/389491087f77991cb563afa9512d67b1a9827e4f
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Artificial Intelligence
In Atomic and Molecular Physics, and Optics
Citations in the corpus
- The classical-quantum boundary for correlations: Discord and related measures (2011, methodology): “A first attempt to evaluate the discord for the twoqubit X-states in a closed form was reported in (Ali et al., 2010), extending the method of (Luo, 2008a).”