Two-level atoms

Robert J. Bettles

Zeng Ke, Mao-Fa Fang

The entanglement properties of the system of two two-level atoms interacting with a single-mode vacuum field are explored. The quantum entanglement between two two-level atoms and a single-mode vacuum field is investigated by using the quantum reduced entropy; the quantum entanglement between two two-level atoms and that between a single two-level atom and a single-mode vacuum field are studied in terms of the quantum relative entropy. The influences of the atomic dipole–dipole interaction on the quantum entanglement of the system are also discussed. Our results show that three entangled states of two atoms–field, atom–atom and atom–field can be prepared via two two-level atoms interacting with a single-mode vacuum field.

Robert J. Bettles

Deng-Yu Zhang

The coherence of two-level atom in a thermal radiation field without rotating wave approximation through an external controllable driving field was investigated. The time evolution properties of non-opposite angle element of two-level atom's reducible density rectangular array was discussed. Coherence properties of two-level atom was studied in degenerate two-photon processes when the two-level atom interacts with an driving field in the thermal radiation field . We obtained the properties of an external driving field when two-level atom's coherence is maintained.

Andrei M. Nemilentsau, Seyyed Ali Hassani, George W. Hanson +1 more

Using the quantum master equation, we demonstrate entanglement of two-level atoms (TLAs) over graphene. Graphene, acting as a structured photonic reservoir, significantly modifies the spontaneous decay rate of a TLA, and is rigorously incorporated into the formalism through the classical electromagnetic Green dyadic. Moreover, entanglement between the TLAs can be improved compared to the vacuum case, due to coupling of the TLAs to TM surface plasmons on graphene. Dynamics of TLAs can be further controlled by graphene biasing.