Broadband circularly polarized thermal radiation from magnetic Weyl semimetals

• DOI: 10.1364/ome.437838
• Publication Date: 2021-09-16T16:00:10Z
• Authors: Yifan Wang; Chinmay Khandekar; Xingyu Gao; Tongcang Li; Dan Jiao; Zubin Jacob
• Keywords: Weyl semimetal; Thermal Radiation

We numerically demonstrate that a planar slab made of magnetic Weyl semimetal (a class topological materials) can emit high-purity circularly polarized (CP) thermal radiation over broad mid- and long-wave infrared wavelength range for significant portion its emission solid angle. This effect fundamentally arises from the strong gyrotropy or nonreciprocity these materials, which primarily depends on momentum separation between nodes in band structure. clarify dependence this underlying physical parameters highlight spectral bandwidth CP increases with increasing nodes. also demonstrate, using recently developed discrete dipole approximation (TDDA) computational method, finite-size bodies semimetals spectrally broadband light, albeit smaller angle compared to slabs. Our work identifies unique fundamental technological prospects engineering designing efficient light sources.