16 citations · 22 across the 4 of their papers we have counts for
4 papers
Nongeneric positive partial transpose states of rank five in dimensions
Leif Ove Hansen, Jan Myrheim
In dimensions, entangled mixed states that are positive under partial transposition (PPT states) must have rank at least four. They are well understood. We say that the…
Visualizing extremal positive maps in unital and trace preserving form
Leif Ove Hansen, Jan Myrheim
We define an entanglement witness in a composite quantum system as an observable having nonnegative expectation value in every separable state. Then a state is entangled if and onl…
Extremal entanglement witnesses
Leif Ove Hansen, Andreas Hauge, Jan Myrheim +1
We study extremal entanglement witnesses on a bipartite quantum system. We define the cone of witnesses as the dual of the set of separable density matrices, thus $\textrm{Tr}\,Ωρ\…
Low rank positive partial transpose states and their relation to product vectors
Leif Ove Hansen, Andreas Hauge, Jan Myrheim +1
It is known that entangled mixed states that are positive under partial transposition (PPT states) must have rank at least four. In a previous paper we presented a classification o…