Comparison of parallel and antiparallel two-qubit mixed states

Purification of two-qubit mixed states

is a frequent choice. However, in practical situations decoherence makes pure states evolve into mixed states and reduces its entanglement. Therefore, in the last years much work has been devoted to understand under which conditions the entanglement that has been lost can be recovered using local operations and classical communication (LOCC). In general there are two frameworks under which the ...

comparison of the amount of debris extruded apically in two rotary techniques: flexmaster and m2

چکیده ندارد.

Optimal discrimination of single-qubit mixed states

Optimal full estimation of qubit mixed states

We obtain the optimal scheme for estimating unknown qubit mixed states when an arbitrary number N of identically prepared copies is available. We discuss the case of states in the whole Bloch sphere as well as the restricted situation where these states are known to lie on the equatorial plane. For the former case we obtain that the optimal measurement does not depend on the prior probability d...

Classification of mixed three-qubit states.

We introduce a classification of mixed three-qubit states, in which we define the classes of separable, biseparable, W, and Greenberger-Horne-Zeilinger states. These classes are successively embedded into each other. We show that contrary to pure W-type states, the mixed W class is not of measure zero. We construct witness operators that detect the class of a mixed state. We discuss the conject...