Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China
Corresponding author (firstname.lastname@example.org
Quantum systems present correlations, which cannot be offered by classical objects. These distinctive correlations are not only considered as fundamental features of quantum mechanics, but more importantly, they are regarded as critical resources for different quantum information tasks. For example, quantum entanglement has been established as the key resource for quantum communication, and quantum discord has been suggested as the resource in deterministic quantum computation with one qubit (DQC1). However, quantification of these resources is very difficult, especially for many-body situations. Here, we introduce a unified numerical method to quantify these resources in general multiqubit states and use it to investigate the robustness of quantum discord in multiqubit permutation-invariant states. Our method paves the way to quantitatively investigate the relation between the potential of quantum technologies and quantum resources, particularly, that between quantum computation and quantum correlations.
Lixin HE acknowledges the support from Chinese National Fundamental Research Program (Grant No. 2011CB921200), National Natural Science Funds for Distinguished Young Scholars, and the Fundamental Research Funds for the Central Universities (Grant No. WK2470000006).
Entanglement of 4-qubit permutation-invariant state, i.e., Eq. (
Quantum discord of 4 and 5-qubit superpositions of two canonical orthonormal GHZ states as in (
(Color online) Quantum discord of $3$ to $6$ qubit states (
(Color online) Quantum discord of 4-qubit mboxstates (
(Color online) Robustness of the turning point: Quantum discord of the original 4-qubit state in (
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