The Research Of Multi-photon Blockade And Dressing Of The Dressed States

The photon blockade could occur for the atom-cavity filed interacting systemwhen a classical pump is injected in Cavity Quantum Electrodynamics(CQED). Thephoton blockade can be understood to be the resonant and off-resonant effects whichare present in the space of the atomic dressed states. As the classical pump is resonantto the dressed states, which are the eigenstates of the atom-cavity field system, thebehaviors are the resonant ones. While the classical pump is off-resonant to thedressed states, such multi-photon excitation will be blocked.The analysis method of dressing of dressed states for the photon blockade isdiscussed on the basis of dressed states of an atom-cavity field interaction. First of all,the multi-photon blockade is described for the one atom and a single-mode fieldsystem. The4-state atom is adopted to replace the two-atom system to analyze theblockade for their similar construction. The method of master equation is adopted forthe description of the4-state case. The newly constructed transition operators for thedressed states is given as well. As varying the frequency of the classical pump, the2-photon blockade, further the multi-photon blockade can be realized in theory. Theblockade induced anti-bunching is discussed in detail. The theoretical and graphicanalysis showed that the anti-bunching effect could be brought about and becomingmuch clear as the influence of the classical pump is more and more strong comparingwith the decays of cavity and atoms. That is, the photon blockaded becomes moreobvious. The second-order coherent function of the field can be used to be thereflection of the two-photon blockade, as well the high-order coherent function of thefield can be that of the multi-photon blockad.