Enhancing nonreciprocal thermal radiation in Weyl semimetals based on optical Tamm states by integrating with photonic crystals

Weyl semimetals (WSs) have shown great potential in realizing nonreciprocal thermal radiation. In this work, we demonstrate that the nonreciprocal thermal radiation can be greatly enhanced in WSs by integrating them with all-dielectric photonic crystals (PCs). By exciting the optical Tamm states between WS films and all-dielectric PCs, the difference between absorption and emission can be as high as 0.94 at the wavelength of 10 μm. The dispersion of the excitation condition and distribution of magnetic field are employed to disclose the physical mechanism. This work indicates that the all-dielectric PC is a promising structure to be integrated with WSs to enhance thermal radiation nonreciprocity.