Quantum logic operations on two distant atoms trapped in two optical-fibre-connected cavities

Abstract

Based on the coupling of two distant three-level atoms in two separate optical cavities connected with two optical fibres, schemes on the generation of several two-qubit logic gates are discussed under the conditions of Δ = δ − 2νcos πk/2 ≫ g/2 and ν ∼ g. Discussion and analysis of the fidelity, gate time and experimental setups show that our schemes are feasible with current optical cavity, atomic trap and optical fibre techniques. Moreover, the atom—cavity—fibre coupling can be used to generate an N-qubit nonlocal entanglement and transfer quantum information among N distant atoms by arranging N atom—cavity assemblages in a line and connecting each two adjacent cavities with two optical fibres.