A scheme of teleporting a superposition of coherent states |α> and |-α> using a 4-partite state, a beam splitter and two phase shifters was proposed by N. Ba An (Phys. Rev. A, 68, 022321, 2003). The author concluded that the probability for successful teleportation is only 1/4 in the limit |α|→∞and 1/2 in the limit |α|→∞. In this paper it is shown that the author’s scheme can be altered slightly so as to obtain an almost perfect teleportation for an appreciable value of|α|2. We find the minimum assured fidelity i.e., the minimum fidelity for an arbitrarily chosen information state, which we write MAF in this paper, for different cases. We also discuss the effect of decoherence on teleportation fidelity. We find that if no photons are counted in both final outputs, MAF, is still nonzero except when there is no decoherence and the initial state (the state to be teleported) is even coherent state. For non-zero photon counts, MAF decreases with increase in |α|2 for low noise. For high noise, however, it increases, attains a maximum value and then decreases with|α|2. The average fidelity depends appreciably on the initial state for low values of |α|2 only.
C. H. Bennett, G. Brassard, C. Crepeau, R. Jozsa, A. Peres and W. K. Wootters, “Teleporting an Unknown Quantum State via Dual Classical and Einstein-Podolsky-Rosen Channels,” Physical Review Letters, Vol. 70, No. 13, 1993, pp. 1895-1899.
C. H. Bennett and S. J. Weisner, “Communication via One- and Two-Particle operators on Einstein-Podolsky-Rosen States,” Physical Review Letters, Vol. 69, No. 20, 1992, pp. 2881-2884. doi:10.1103/PhysRevLett.69.2881
M. K. Mishra, A. K. Maurya and H. Prakash, “Two-Way Quantum Communication: Secure Quantum Information Exchange,” Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 44, 2011, Article ID: 115504.
M. K Mishra and H. Prakash “Teleportation of a two Mode Entangled Coherent States,” Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 43, 2010, Article ID: 185501.
H. N. Phien and N. Ba An, “Quantum Teleportation of an Arbitrary Two-Mode Coherent State Using Only Linear Optics Elements,” Physics Letters A, Vol. 372, No. 16, 2008, pp. 2825-2829. doi:10.1016/j.physleta.2007.12.069
D. Bouwmeester, J. W. Pan, K. Mattle, M. Eibl, H. Weinfurter and A. Zeilinger, “Experimental Entanglement Swapping: Entangling Photons that Never Interacted,” Nature, Vol. 390, 1997, pp. 575.
D. Boschi, S. Branca, F. De Martini, L. Hardy and S. Popescu, “Experimental Realization of Teleporting an Unknown Pure Quantum State via Dual Classical and Einstein-Podolsky-Rosen Channels,” Physical Review Letters, Vol. 80, No. 6, 1998, pp. 1121-1125.
T. Ide, H. F. Hofmann, T. Kobayashi and A. Fursawa, “Continuous-Variable Teleportation Of Single-Photon States,” Physical Review A, Vol. 65, No. 1, 2001, Article ID: 012313. doi:10.1103/PhysRevA.65.012313
H. Jeong, W. Son, M. S. Kim, D. Ahn and C. Brukner, “Quantum Nonlocality Test for Continuous-Variable States with Dichotomic Observables,” Physical Review A, Vol. 67, No. 1, 2003, Article ID: 012106.
H. Jeong, M. S. Kim and J. Lee, “Quantum-Information Processing for a Coherent Superposition State via a Mixed Entangled Coherent Channel,” Physical Review A, Vol. 64, No. 5, 2001, Article ID: 052308.
H. Prakash, N. Chandra, R. Prakash and Shivani, “Entanglement Diversion between Two Pairs of Entangled Coherent States: Fidelity and Decoherence,” International Journal of Modern Physics B, Vol. 23, No. 4, 2009, p. 585.
H. Prakash, N. Chandra, R. Prakash and Shivani, “Effect of Decoherence on Fidelity in Teleportation of Entangled Coherent States,” International Journal of Quantum Information, Vol. 6, No. 5, 2008, p. 1077.
H. Prakash, N. Chandra, R. Prakash and Shivani, “Effect of Decoherence on Fidelity in Teleportation Using Entangled Coherent States,” Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 40, No. 8, 2007, p. 1613. doi:10.1088/0953-4075/40/8/012
H. Prakash, N. Chandra, R. Prakash and Shivani, “Improving the Entanglement Diversion between Two Pairs of Entangled Coherent States,” International Journal of Modern Physics B, Vol. 24, No. 17, 2010, p. 3331.