  Scheme to prepare three-dimensional entangled state between a pair of Rydberg
atoms is proposed via dissipative dynamics and Electromagnetic Induced
Transparency (EIT) associated with the single-atom dark state. The prepared
entangled state is the dark state of the whole system. The schemes are feasible
no matter the system initially in arbitrary purity or mixed states and do not
have accurate requirements on evolution time. In contrast to most of the former
Rydberg-atombased dissipative schemes, the Rydberg-Rydberg interaction (RRI)
strength do not need to satisfy a certain relation with laser detuning since it
works in the blockade as well as intermediate regimes.
