SlicedBREAD: Enhancing Axion Detection Efficiency in BREAD with Dielectric Stacks

The Broadband Reflector Experiment for Axion Detection (BREAD) searches for wave-like dark matter within a gigahertz to terahertz frequency range. The experiment employs a cylindrical metal barrel to facilitate the conversion of axion or dark photon dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. Its extension, SlicedBREAD, will incorporate dielectric stacks within the barrel to further enhance photon coupling. Dielectric stacks can significantly increase the power from axion-photon conversion. We conduct simulations to evaluate the power boost factor and sensitivity, along with the fabrication and testing of various stack designs. By optimizing the stack geometry and material properties, SlicedBREAD aims to achieve the sensitivity required for axion detection in the W band (75–110 GHz). In this talk, we will present progress in the development of a prototype stack as well as preliminary results, demonstrating the potential for increased axion detection sensitivity.