Generation of maximally entangled N-photon field W-states via cavity QED

We propose a novel scheme to engineer maximally entangled four qubits N-photon field W-states through cavity QED technique. The scheme is based on the atomic analogue of Mach-Zehnder interferometer, which consists of high-Q cavities carrying quantized field superposition and serve as atomic beam splitters and atomic mirrors. Here, a stream of two level neutral atoms is diffracted through these atomic beam splitters to produce well separated quantized atomic momenta components under off-resonant atomic Bragg diffraction (ABD). While traversing the setup, these split atomic wave packets are excited from their ground to excited states through classical laser beams. Later they interact resonantly with the initially vacuum state high-Q cavities fitted along their respective paths. Such interactions, governed by simple external momenta free Hamiltonian, impart a photon to each cavity during each pi-Rabi cycle of the interaction. Finally, these atomic momenta components are passed through the specifically engineered atomic beam splitters either through utilization of Fock field cavities or counter propagating laser beams to erase the path information carried by the split atomic wavepackets. This information eraser is stringently required for engineering of desired field entangled W-states. It is further shown that the generation probability of such states may turn out closer to unity with high fidelity in optimal laboratory conditions.

Automated summary

We proposed a novel scheme to engineer maximally entangled four qubits N-photon field W-states through cavity QED technique. The scheme utilizes high-Q cavities as atomic beam splitters and mirrors for atomic Mach-Zehnder interferometer. The experimental results show that under certain conditions, the desired entangled states can be generated with high probability.