4 research outputs found
Concurrence classes for an arbitrary multi-qubit state based on positive operator valued measure
In this paper, we propose concurrence classes for an arbitrary multi-qubit
state based on orthogonal complement of a positive operator valued measure, or
POVM in short, on quantum phase. In particular, we construct concurrence for an
arbitrary two-qubit state and concurrence classes for the three- and four-qubit
states. And finally, we construct and class concurrences for
multi-qubit states. The unique structure of our POVM enables us to distinguish
different concurrence classes for multi-qubit states.Comment: 8 page
Measures and dynamics of entangled states
We develop an original approach for the quantitative characterisation of the entanglement properties of, possibly mixed, bi- and multipartite quantum states of arbitrary finite dimension. Particular emphasis is given to the derivation of reliable estimates which allow for an efficient evaluation of a specific entanglement measure, concurrence, for further implementation in the monitoring of the time evolution of multipartite entanglement under incoherent environment coupling. The flexibility of the technical machinery established here is illustrated by its implementation for different, realistic experimental scenarios