29 citations · 56 across the 5 of their papers we have counts for
7 papers
Physical Purification of Quantum States
M. Kleinmann, H. Kampermann, T. Meyer +1
We introduce the concept of a physical process that purifies a mixed quantum state, taken from a set of states, and investigate the conditions under which such a purification map e…
On the generalization of quantum state comparison
M. Kleinmann, H. Kampermann, D. Bruss
We investigate the unambiguous comparison of quantum states in a scenario that is more general than the one that was originally suggested by Barnett et al. First, we find the optim…
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…
Quantum Key Distribution: from Principles to Practicalities
Dagmar Bruß, Norbert Lütkenhaus
We review the main protocols for key distribution based on principles of quantum mechanics, describing the general underlying ideas, discussing implementation requirements and poin…