1,339 research outputs found
Perfect Test of Entanglement for Two-level Systems
A 3-setting Bell-type inequality enforced by the indeterminacy relation of
complementary local observables is proposed as an experimental test of the
2-qubit entanglement. The proposed inequality has an advantage of being a
sufficient and necessary criterion of the separability. Therefore any entangled
2-qubit state cannot escape the detection by this kind of tests. It turns out
that the orientation of the local testing observables plays a crucial role in
our perfect detection of the entanglement.Comment: 4 pages, RevTe
Classifying N-qubit Entanglement via Bell's Inequalities
All the states of N qubits can be classified into N-1 entanglement classes
from 2-entangled to N-entangled (fully entangled) states. Each class of
entangled states is characterized by an entanglement index that depends on the
partition of N. The larger the entanglement index of an state, the more
entangled or the less separable is the state in the sense that a larger maximal
violation of Bell's inequality is attainable for this class of state.Comment: 4 pages, 3 figure
- …