Decay and storage of multiparticle entangled states of atoms in   collective thermostat
  We derive a master equation describing the collective decay of two-level atoms inside a single mode cavity in the dispersive limit. By considering atomic decay in the collective thermostat, we found a decoherence-free subspace of the multiparticle entangled states of the W-like class. We present a scheme for writing and storing these states in collective thermostat. 
A.M. Basharov, V.N. Gorbachev, A.A. Rodichkina