Transmission interference tuned by an external static magnetic field in a two-slit structure

We present a near-field analysis of transmitted field interference tuned by an external static magnetic field on an n -doped semiconductor film drilled by two slits at terahertz frequency. It is found that the peak magnetic field intensity of the interference pattern between the two slits can be strengthened twice as against that of zero external static magnetic field. The physical origin comes from the interaction between surface plasmon polaritons (SPPs) and radiative evanescent field components launched by each slit on the transmitted surface, and also from the considerable alteration of the SPPs, caused by the external static magnetic field.