Enhanced Kerr nonlinearity in a quantized four-level graphene nanostructure
Solookinejad Ghahraman, Panahi M, Ahmadi E, Hossein Asadpour Seyyed†,
       

Linear absorption (solid line) and Kerr nonlinearity (dashed line) versus different quantities of Rabi frequency Ωc for (a) θ = 0 and (b) θ = π/6. The other parameters are the same as Fig. 2.