Si/InAs/Ag metamaterial for strong nonreciprocal thermal emitter with dual polarization under a 0.9 T magnetic field

The current nonreciprocal thermal emitter has been proven to completely violate the previous Kirchhoff's law. And the majority of related nonreciprocal devices operate under single polarization with few dual-polarization nonreciprocal designs. Therefore, dual-polarization nonreciprocal thermal radiation has great research prospects. In addition, many previous designs of nonreciprocal devices required external magnetic field energy of 3 T even higher, which is difficult to meet in practical applications. Therefore, this article investigates the strong nonreciprocal dual-polarization thermal radiation of cuboid arrays under lower external magnetic field. It is constructed by silicon, silver layer, InAs layer, and cuboid arrays. Finally, dual-polarization nonreciprocal radiation was achieved in a magnetic field of only 0.9 T, and the nonreciprocal efficiency has been significantly improved. The physical phenomenon of dual-polarization strong nonreciprocal radiation exhibited by the proposed device was explained by utilizing the electromagnetic field distribution at the resonant wavelength. It can also maintain good nonreciprocal properties under different structural parameters. Therefore, our proposed solution provides new opportunities for energy harvesting and thermal radiation control.