Atomic Entangled States Research Articles

Preparation of Entangled Atomic States via Atoms Interacting with the Cavity-Field in SU(1,1) Coherent State

A new scheme is presented for generating atomic entangled states based on atoms-cavity-field interaction. After suitably prepared Ξ-type atoms interact with the cavity-field in the SU(1,1) coherent state initially, a subsequent measurement on this field projects the atoms onto the entangled states.

Cavity-loss-induced generation of entangled atoms

We discuss the generation of entangled states of two two-level atoms inside an optical resonator. When the cavity decay is continuously monitored, the absence of photon counts is associated with the presence of an atomic entangled state. In addition to being conceptually simple, this scheme can be demonstrated with presently available technology. We describe how such a state is generated through conditional dynamics, using quantum jump methods, including both cavity damping and spontaneous emission decay, and evaluate the fidelity and relative entropy of entanglement of the generated state compared with the target entangled state.

Creation of entangled states of distant atoms by interference

We propose a scheme to create distant entangled atomic states. It is based on driving two (or more) atoms with a weak laser pulse, so that the probability that two atoms are excited is negligible. If the subsequent spontaneous emission is detected, the entangled state is created. We have developed a model to analyze the fidelity of the resulting state as a function of the dimensions and location of the detector, and the motional properties of the atoms.

Entangling atoms in photonic crystals

We propose a method for entangling a system of two-level atoms in photonic crystals. The atoms are assumed to move in void regions of a photonic crystal. The interaction between the atoms is mediated either via a defect mode or via resonant dipole-dipole interaction. We show that these interactions can produce pure entangled atomic states. We analyze the problem with parameters typical for currently existing photonic crystals and Rydberg atoms. We show that the atoms can emerge from photonic crystals in entangled states. Depending on the linear dimensions of the crystal and on their velocity of the entangled atoms can be separated by tens of centimeters.

Teleportation of a cavity-radiation-field state: An alternative scheme.

We present an alternative and experimentally feasible scheme to realize the teleportation of a cavity mode in a coherent superposition of zero-, one-, and two-photon field states. Particular nonmaximally entangled states of two-level atoms and particular cavity modes are employed and their preparation is discussed. A Ramsey-type arrangement, together with pointer atoms, is required to prepare the atomic entangled states as well as to read out the cavity system. Basically, the pointer atoms induce the state-vector collapse of the field in the cavity system and indicate, through their detection, the measurement result. \textcopyright{} 1996 The American Physical Society.