Few-photon single-atom cavity QED with input-output formalism in Fock   Space
  The Jaynes-Cummings (JC) system, which describes the interaction between a cavity and a two-level atom, is one of the most important systems in quantum optics. We obtain analytic solutions for the one- and two-photon transport in a waveguide side-coupled to the JC system using input-output formalism in Fock space. With these results, we discuss the conditions under which the JC system functions as a photon switch for waveguide photons in both the strong and weak coupling regimes 
Eden Rephaeli and Shanhui Fan
quant-ph cond-mat.mes-hall