How entangled can two couples get?
Quantum Physics
2009-11-06 v2
Abstract
We describe a pure state of four qubits whose single-qubit density matrices are all maximally mixed and whose average entanglement as a system of two pairs of qubits appears to be maximal.
Keywords
Cite
@article{arxiv.quant-ph/0005013,
title = {How entangled can two couples get?},
author = {A. Higuchi and A. Sudbery},
journal= {arXiv preprint arXiv:quant-ph/0005013},
year = {2009}
}
Comments
9 pages. Note added about the robustness of the entanglement in the four-qubit state described in the paper. Version to be published in Phys. Lett. A