The enhanced nonreciprocal radiation with topological interface states

The enhanced nonreciprocal radiation effect based on topological interface states is studied, which is realized by inserting a Weyl semimetal film between two asymmetric topological photonic crystals. It is found that nearperfect nonreciprocal radiation is realized for the wavelength of 10 mu m under the incident angle of 60 degrees, which is attributed to the topological interface state excited at the boundary between two asymmetric topological photonic crystals, and it is revealed by investigating the magnetic field intensity distribution. Besides, it is shown that the designed structure can also be expanded to achieve strong tri-band nonreciprocal radiation and singband nonreciprocal radiation with larger nonreciprocity. The concepts proposed in this work should be attractive for the design of novel energy harvesting devices and infrared stealth.