Cooperative light scattering on an atomic system with degenerate   structure of the ground state
  We present here a microscopic analysis of the cooperative light scattering on an atomic system consisting of \Lambda-type configured atoms with the spin-degenerate ground state. The results are compared with a similar system consisting of standard "two-level" atoms of the Dicke model. We discuss advantages of the considered system in context of its possible implications for light storage in a macroscopic ensemble of dense and ultracold atoms. 
Alexandra S. Sheremet, Alisa D. Manukhova, Nickolay V. Larionov,   Dmitriy V. Kupriyanov
physics.atom-ph quant-ph