100 research outputs found
Applications of quantum cryptographic switch: Various tasks related to controlled quantum communication can be performed using Bell states and permutation of particles
Recently, several aspects of controlled quantum communication (e.g.,
bidirectional controlled state teleportation, controlled quantum secure direct
communication, controlled quantum dialogue, etc.) have been studied using
-qubit () entanglement. Specially, a large number of schemes for
bidirectional controlled state teleportation are proposed using -qubit
entanglement (). Here, we propose a set of protocols to
illustrate that it is possible to realize all these tasks related to controlled
quantum communication using only Bell states and permutation of particles
(PoP). As the generation and maintenance of a Bell state is much easier than a
multi-partite entanglement, the proposed strategy has a clear advantage over
the existing proposals. Further, it is shown that all the schemes proposed here
may be viewed as applications of the concept of quantum cryptographic switch
which was recently introduced by some of us. The performances of the proposed
protocols as subjected to the amplitude damping and phase damping noise on the
channels are also discussed.Comment: 12 pages, 3 figure
A General Method for Selecting Quantum Channel for Bidirectional Controlled State Teleportation and Other Schemes of Controlled Quantum Communication
Recently, a large number of protocols for bidirectional controlled state
teleportation (BCST) have been proposed using -qubit entangled states
() as quantum channel. Here, we propose a general method of
selecting multi-qubit quantum channels suitable for BCST and show that
all the channels used in the existing protocols of BCST can be obtained using
the proposed method. Further, it is shown that the quantum channels used in the
existing protocols of BCST forms only a negligibly small subset of the set of
all the quantum channels that can be constructed using the proposed method to
implement BCST. It is also noted that all these quantum channels are also
suitable for controlled bidirectional remote state preparation (CBRSP).
Following the same logic, methods for selecting quantum channels for other
controlled quantum communication tasks, such as controlled bidirectional joint
remote state preparation (CJBRSP) and controlled quantum dialogue, are also
provided.Comment: 8 pages, no figur
Design and experimental realization of an optimal scheme for teleportion of an -qubit quantum state
An explicit scheme (quantum circuit) is designed for the teleportation of an
-qubit quantum state. It is established that the proposed scheme requires an
optimal amount of quantum resources, whereas larger amount of quantum resources
has been used in a large number of recently reported teleportation schemes for
the quantum states which can be viewed as special cases of the general
-qubit state considered here. A trade off between our knowledge about the
quantum state to be teleported and the amount of quantum resources required for
the same is observed. A proof of principle experimental realization of the
proposed scheme (for a 2-qubit state) is also performed using 5-qubit
superconductivity-based IBM quantum computer. Experimental results show that
the state has been teleported with high fidelity. Relevance of the proposed
teleportation scheme has also been discussed in the context of controlled,
bidirectional, and bidirectional-controlled state teleportation.Comment: 11 pages 4 figure
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