59 citations · 72 across the 7 of their papers we have counts for
7 papers · 1 filter
The separability versus entanglement problem
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein +1
We review the problem of discriminating entangled states from separable states for bipartite systems. We formally define what entangled states are, present some important criteria…
Simplifying Schmidt number witnesses via higher-dimensional embeddings
Florian Hulpke, Dagmar Bruss, Maciej Lewenstein +1
We apply the generalised concept of witness operators to arbitrary convex sets, and review the criteria for the optimisation of these general witnesses. We then define an embedding…
Finite size effects in entangled rings of qubits
T. Meyer, U. V. Poulsen, K. Eckert +2
We study translationally invariant rings of qubits with a finite number of sites N, and find the maximal nearest-neighbor entanglement for a fixed z component of the total spin. Fo…
Entanglement properties of composite quantum systems
K. Eckert, O. Gühne, F. Hulpke +6
We present here an overview of our work concerning entanglement properties of composite quantum systems. The characterization of entanglement, i.e. the possibility to assert if a g…
Bound entanglement for continuous variables is a rare phenomenon
Pawel Horodecki, J. Ignacio Cirac, Maciej Lewenstein
We discuss the notion of bound entanglement (BE) for continuous variables (CV). We show that the set of non--distillable states (NDS) for CV is nowhere dense in the set of all stat…
Separability and entanglement in 2xN composite quantum systems
M. Lewenstein, J. I. Cirac, S. Karnas
We show that all density operators of 2--dimensional quantum systems that remain invariant after partial transposition with respect to the first system are separable. Bas…