N -qubit W states are determined by their bipartite marginals
Preeti Parashar, Swapan Rana · Physical Review A · 2009
We prove that the most general $W$ class of $N$-qubit states are uniquely determined among arbitrary states (pure or mixed) by just their bipartite reduced density matrices. Moreover, if we consider only pure states, then $(N\ensuremath{-}1)$ of them are shown to be sufficient.