Abstract

We propose a method for transferring the quantum state of two internally-translationally entangled atoms to that of two photons, by the following procedure. A cold, well-collimated source produces a diatomic molecule (e.g., Na₂) having velocity v_y. The molecule is dissociated by stimulated Raman adiabatic passage (STIRAP) to an energy-specific state of two atoms, A and B [1]. Each atom can occupy one of the two hyperfine states of its ground state (3S_1/2), labeled |g₁⟩ or |g₂⟩-In the center-of-mass frame, the dissociating atoms move along the x axis with velocities ±v_x, which depend on the internal excitation state of the system: the zero-excitation state |g₁⟩_A |g₁⟩_B, double-excitation state |g₂⟩_A |g₂⟩_B and single-excitation states, |g₁⟩_A |g₂⟩_B and |g₂⟩_A |g₁⟩_B. Two empty, high-Q optical cavities, a and b, aligned along the z axis, are placed at positions such that only a pair of atoms sharing the single excitation will pass through both cavities, all other outcomes being idle events. The cavity fields partially overlap a classical pump field E_p having the frequency ω_p and propagating along the x axis. Each cavity supports two modes with the frequencies ${\omega }_{1,2}^{(a)}={\omega }_p-k_p{v}_x-\left({\omega }_f-{\omega }_{g_{1,2}}\right)$ and ${\omega }_{1,2}^{(b)}={\omega }_p+k_p{v}_x-\left({\omega }_f-{\omega }_{g_{1,2}}\right)$, respectively.

© 2001 EPS