Significant enhancement of dual-polarization nonreciprocity by twisted <i>α</i>-MoO₃/Weyl semimetals heterostructure

The twisted <i>α</i>-MoO₃ has been widely utilized in the near-field radiative heat transfer, as well as the far-field thermal radiation. However, the valuable nonreciprocal thermal radiation between Weyl semimetals and twisted <i>α</i>-MoO₃ has yet to be investigated. In this work, the twisted <i>α</i>-MoO₃/Weyl semimetals heterostructures separated by Ge dielectric layer are studied to find out the relationship between the twisted <i>α</i>-MoO₃ and the dual-polarization nonreciprocity. Through research on polarization conversions, the enhancement of dual-polarization nonreciprocity is confirmed to arise from the increment of discrepancy of the co-polarized reflectivity components, which depends on the twisted angles. The twisted <i>α</i>-MoO₃ breaks the mirror symmetry and rotational symmetry, providing nonreciprocal absorption effects for TE polarization. The study on electric field distributions reveals that the dual-polarization nonreciprocity arises from the excitation of Fabry-Perot modes in Ge dielectric layer. The proposed scheme incorporates twisted optics and nonreciprocal thermal radiation, which provides an effective solution for the design of the dual-polarization nonreciprocal thermal emitters.