Control of atomic entanglement by the dynamic Stark effect

Abstract

We study the entanglement properties of two three-level Rydberg atoms passing through a singlemode cavity. The interaction of an atom with the cavity field allows the atom to make a transition from the upper most (lower most) to the lower most (upper most) level by emission (absoprtion) of two photons via the middle level. We employ an effective Hamiltonian that describes the system with a Stark shifted two-photon atomic transition. We compute the entanglement of formation of the joint two-atom state as a function of Rabi angle gt. It is shown that the Stark shift can be used to enhance the magnitude of atomic entanglement over that obtained in the resonant condition for certain parameter values. We find that though the two-atom entanglement generally diminishes with the increase of the two-photon detuning and the Stark shift, it is possible to sustain the entanglement over a range of interaction times by making the detuning and the Stark shift compensate each other. Similar characteristics are obtained for a thermal state cavity field too.

Entanglement generation by interaction with semiclassical radiation

“…The resonant interaction of a field mode in excited states with two atoms has been investigated theoretically in [6][7][8] for simultaneous interaction and [9,10] for consecutive interaction, revealing wavepacket splitting, slow atomic state evolution, and collapse-revival dynamics of entanglement similar to those observed in one atomfield system. The off-resonant interaction of a field wave packet with two atoms was studied experimentally and theoretically in [11,12] as a means of measurement of the cavity decay rate and its effect on the dephasing of Schrödinger cat states.…”

Control of entanglement between two atoms by the Stark shift

“…Recently, the problem of controlling entanglement by dynamic Stark effect has attracted much attention. [15−17] Ghosh et al [15] have found that the Stark shift can be used to enhance the magnitude of atomic entanglement. In Ref.…”

Anabiosis of phase distribution of a three-level atom

“…Therefore, each atom in the system can be treated as an effective two-level system involving its |e, α and |g, α electronic states. This is done by means of an adiabatic elimination of the intermediate state [20,21] assuming that the initial states of the electron for the system include only the states |e, α and |g, α . The Hamiltonian describing such a system can be written in the interaction representation aŝ…”