document: The fully entangled fraction as an inclusive measure of entanglement applications Characterizing entanglement in all but the simplest case of a two qubit pure state is a hard problem , even understanding the relevant experimental quantities that are related to entanglement is difficult . It may not be necessary , however , to quantify the entanglement of a state in order to quantify the quantum information processing significance of a state . It is known that the fully entangled fraction has a direct relationship to the fidelity of teleportation maximized under the actions of local unitary operations . In the case of two qubits we point out that the fully entangled fraction can also be related to the fidelities , maximized under the actions of local unitary operations , of other important quantum information tasks such as dense coding , entanglement swapping and quantum cryptography in such a way as to provide an inclusive measure of these entanglement applications . For two qubit systems the fully entangled fraction has a simple known closed-form expression and we establish lower and upper bounds of this quantity with the concurrence . This approach is readily extendable to more complicated systems
doc_bio_tags: O B I I O O O O O B O O B O O O O O O O O B I I I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O B I I O O O O O O O O O O B I I O O O O O O B O B O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O B O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: entanglement two qubit pure state quantum information processing fully entangled fraction fidelity teleportation quantum cryptography
abstractive_keyphrases: entanglement swapping