  A proposal for the generation of singlet states of three $\Lambda$-type
Rydberg atoms is presented. The singlet state is prepared through the
combination of a Rydberg state and an EPR pair, and the scheme relies on the
Rydberg blockade effect which prevents the simultaneous excitation of the two
atoms to a Rydberg state. In addition, some frequency detuning between lasers
and atomic transitions is set to eliminate the degenerate of the two ground
states. And finally, a series of numerical simulations are made to show the
feasibility of the scheme.
