Dynamically controlled optical nonreciprocity of a double-ladder system with spontaneously generated coherence in moving atomic optical lattice
Ba Nuo1, †, Wu Xiang-Yao1, Li Dong-Fei1, Wang Dan1, Fei Jin-You1, Wang Lei2
       

(a) Four-level double ladder-type system with SGC. (b) A real four-level N-type atomic system. The former is equivalent to the latter in the dressed-state picture of the coupling field .