Manoj K Mishra

Teleportation of a two-mode entangled coherent state encoded with two-qubit information

We propose a scheme to teleport a two-mode entangled coherent state encoded with two-qubit information, which is better than the two schemes recently proposed by Liao and Kuang (2007 J. Phys. B: At. Mol. Opt. Phys. 40 1183) and by Phien and Nguyen (2008 Phys. Lett. A 372 2825) in that our scheme gives higher value of minimum assured fidelity and minimum average fidelity without using any nonlinear interactions. For involved coherent states | ± α, minimum average fidelity in our case is ≥0.99 for |α| ≥ 1.6 (i.e. |α|2 ≥ 2.6), while previously proposed schemes referred above report the same for |α| ≥ 5 (i.e. |α|2 ≥ 25). Since it is very challenging to produce superposed coherent states of high coherent amplitude (|α|), our teleportation scheme is at the reach of modern technology.

Two-way quantum communication: ‘secure quantum information exchange’

In this paper, we generalize the secure quantum information exchange (SQIE) protocol, originally proposed by the authors [J. Phys. B: At. Mol. Opt. Phys. 44 (2011) 115504] for secure exchange of one qubit information with each of Alice and Bob, to the case of secure exchange of quantum information of arbitrary qubits with Alice and Bob. We also discuss security of the original and generalized SQIE protocols with respect to the number of qubits with controller, Charlie.

Bipartite coherent-state quantum key distribution with strong reference pulse

We propose an optical scheme for quantum key distribution in which bits are encoded in relative phases of four bipartite weak coherent states

Two-way quantum communication: Generalization of secure quantum information exchange to quantum network

{|\alpha, \alpha\rangle, |-\alpha, -\alpha\rangle, |-\alpha, \alpha\rangle}

Two-Way Quantum Communication: `Secure Quantum Information Exchange'-II. Generalization to Arbitrary Number of Qubits

and

Quantum Teleportation within a Quantum Network

{|\alpha, -\alpha \rangle}