High success standard quantum teleportation using entangled coherent state and two-level atoms in cavities

Abstract

We propose here a new idea for quantum teleportation of superposed coherent state which is not only almost perfect, in principle, but also feasible experimentally. We use entangled resource $\sim |α,\fracα{\sqrt{2}}\rangle-|-α,-\fracα{\sqrt{2}}\rangle$ in contrast with the usual $\sim |α,α\rangle-|-α,-α\rangle$ (both states unnormalized). Bob receives state which is then superposition of the states $|\pm \fracα{\sqrt{2}}\rangle$ . Bob mixes these with even or odd coherent states involving superposition of states $|\pm \fracα{\sqrt{2}}\rangle$ to obtain a two-mode state which is one of $\sim |I,0\rangle \pm |0,I\rangle$, $|I\rangle$ being the information state. Bob then obtains the teleported information by using interaction of one of these modes in two cavities with resonant two-level atoms. This scheme results in average fidelity of $\simeq 0.95$ for $|α|^2 \simeq 10$, which increases with $|α|^2$ and tends to 1 asymptotically, varying as $1-\frac{π^2}{16|α|^2}+\frac{π^2(π^2+8)}{256|α|^4}$ for large values of $|α|^2$.