Loss induced high efficient Lorentz nonreciprocal metasurfaces

Lorentz nonreciprocal metasurfaces rely on breaking all symmetries related to energy flow reciprocity. We numerically design a metasurface made of dimer unit cell to achieve nonreciprocity. The dimer consists of a gyromagnetic and lossy dielectric cylinder. Under the biased magnetic field, the TE (nonzero electric field out of plane) polarized plane wave at normal incident in different direction exhibit nonreciprocal transmission. We successfully employ the multiple scattering theory (MST) up to the dominant resonant modes of cylinders to describe the numerical nonreciprocal feature. The nonreciprocal mechanism can be revealed by the eigen-response theory that different direction incidence comprises of different portion of lossy mode which will favour to excite the lossy dielectric cylinder, leading to nonreciprocal transmission.