Fig. 1

a Schematic diagram of the silver nanoring/half nanoring, the geometric parameters are Rin = 310 nm, Rout = 400 nm, t = 40 nm and p = 1000 nm. b The top view corresponding to the single cell of nanostructure is arranged right. The orientation angle of the half nanoring shifting from the axle wire (along the y-direction) of the concentric system is θ