2 research outputs found
Operational criterion for controlled dense coding with non-trivial tripartite entangled states
In this paper, we provide an operational criterion for controlled dense
coding with a general class of three-qubit partially entangled states. A
general three-qubit pure entangled state can be classified into two
inequivalent classes according to their genuine tripartite entanglement. We
claim that if a three-qubit state shows entanglement characteristic similar to
-class then such non-trivial tripartite states are useful in {\it
controlled dense coding} whereas states belonging to -class are not useful
for that. We start with a particular class of non-trivial partially entangled
states belonging to -class and show that they are effective in controlled
dense coding. Then we cite several other examples of different types of
tripartite entangled states to support our conjecture.Comment: Accepted for publication in "Pramana Journal of Physics", (Indian
Academy of Sciences, Springer
Study on Entanglement and its Utility in Information Processing
The efficacies of maximally and that of non-maximally entangled mixed states
as teleportation channels have been studied. A new class of non-maximally
entangled mixed states have been proposed also. Their advantages as quantum
teleportation channels over existing non-maximally entangled mixed states have
been verified. The mixed states can also be generated using quantum cloning
machines. We have also studied how one can utilize the mixed entangled states
obtained as output from a state independent quantum cloning machine in
teleportation and dense coding. Mixed states can also be used in secret
sharing. A new protocol of secret sharing has been devised where four parties
are involved. One of them is honest by nature and the other is dishonest. The
dishonest one has two associates who are also involved in the protocol. It has
been shown how the honest party, by using quantum cloning machine, can prevent
the dishonest party from communicating the secret message to his accomplices. A
relation has been established among entanglement of the initially prepared
state, entanglement of the mixed state received by the recipients of the
dishonest one after honest party applies the cloning scheme and the cloning
parameters of the cloning machine. The usefulness of tri-partite and
four-partite entangled states in controlled dense coding has been discussed.
The thesis concludes with the summary and possible courses of future works.Comment: Ph. D Thesis, Department of Applied Mathematics, University of
Calcutta (2016). Published in newweb.bose.res.in>academic program