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Continuous-variable quantum teleportation through lossy channels

A. V. Chizhov·L. Knöll·D. -G. Welsch
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Abstract

The ultimate limits of continuous-variable single-mode quantum teleportation due to absorption are studied, with special emphasis on (quasi-)monochromatic optical fields propagating through fibers. It is shown that even if an infinitely squeezed two-mode squeezed vacuum were used, the amount of information that would be transferred quantum mechanically over a finite distance is limited and effectively approaches to zero on a length scale that is much shorter than the (classical) absorption length. Only for short distances the state-dependent teleportation fidelity can be close to unity. To realize the largest possibly fidelity, an asymmetrical equipment must be used, where the source of the two-mode squeezed vacuum is nearer to Alice than to Bob and in consequence the coherent displacement performed by Bob cannot be chosen independently of the transmission lengths.

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A. V. Chizhov, L. Knöll, D. -G. Welsch. 2001-10-05. Continuous-variable quantum teleportation through lossy channels. https://doi.org/10.1103/physreva.65.022310

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