Comments on Multipartite Entanglement in Four-qubit Graph States

The following comments are based on the article byM. Jafarpour and L. Assadi [Eur. Phys. J. D 70, 62(2016), doi:10.1140/epjd/e2016-60555-5] which bymeans of Scott measure or generalized Meyer-Wallach measure the entanglement quantity offour-qubit graph states has been calculated. We areto reveal that the Scott measure m Q nominateslimits for m which would prevent us fromcalculating 3 Q in four-qubit system. Incidentally ina counterexample we will confirm as it wasrecently concluded in the mentioned article, the2 Q quantity is not necessarily always greater than3 Q in all the graph states.

کلیدواژه ها:

Entanglement ، Graph states ، Qubit