Entangled States of Atoms upon Interaction with Narrowband Light

The process of resonant interaction of light with two-level atoms in the absence of relaxation is considered. For a special form of initial conditions, simple and exact solutions are found that describe coherent processes leading to the appearance of many-particle entangled W-class states. These processes can be used for preparation and transformation of entangled states, in particular, for problems of quantum memory and generation of entangled atomic chains