Generation of multi-photon Fock states by bichromatic adiabatic passage:   topological analysis
  We propose a robust scheme to generate multi-photon Fock states in an atom-maser-cavity system using adiabatic passage techniques and topological properties of the dressed eigenenergy surfaces. The mechanism is an exchange of photons from the maser field into the initially empty cavity by bichromatic adiabatic passage. The number of exchanged photons depends on the design of the adiabatic dynamics through and around the conical intersections of dressed eigenenergy surfaces. 
M. Amniat-Talab, S. Lagrange, S. Guerin, H.R. Jauslin