Quantum teleportation and information transfer in the system of two resonant atoms

Abstract

The resonance transfer of quantum information from one two-level atom to another that is at an arbitrary distance from the former one is investigated. The symmetric $\Psi_s$ and antisymmetric $\Psi_a$ states of the two-atom system are considered taking into account dipole-dipole interaction between atoms of this system. The closed-form analytical expressions for shifts and widths of the considered collective states $\Psi_{s(a)}$ of two identical two-level atoms located at an arbitrary distance from each other. In the quite general considerations the system of nonstationary equations describing separately evolution of states amplitudes of the compound-system ``$A(1)$ atom+$A(2)$ atom+field'' in symmetric and antisymmetric channels at absorption of a photon by one of the compound-system atoms. Three cases of the obtained solutions for amplitudes of possible states of the compound-system at resonance and nonresonance absorption of a photon are considered. It has been shown that when atoms are at an infinite distance from one another, so that there is no dipole-dipole interaction of atoms, quantum information can be transferred from one atom to another with a characteristic time considerably shorter than the time it takes for a photon to cover the interatomic distance. This effect is referred to as the effect of quantum teleportation in a system of resonance atoms.