Open AccessWitnessing quantum entanglement in ensembles of nitrogen–vacancy centers coupled to a superconducting resonator
Author(s) -
Yusef Maleki,
А. М. Желтиков
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.017849
Subject(s) - quantum entanglement , spins , qubit , physics , resonator , quantum metrology , quantum mechanics , superconductivity , w state , quantum state , density matrix , quantum , condensed matter physics , optics , quantum network
A hybrid quantum device consisting of three ensembles of nitrogen-vacancy centers (NVEs) whose spins are collectively coupled to a superconducting coplanar waveguide resonator is shown to enable the generation of controllable tripartite macroscopic entangled states. The density matrix of such NVEs can be encoded to recast a three-qubit system state, which can be characterized in terms of the entanglement witnesses in relation to the Greenberger-Horne-Zeilinger (GHZ) states. We identify the parameter space within which the generated entangled states can have an arbitrarily large overlap with GHZ states, indicating an enhanced entanglement in the system.