Yannis Semertzidis(IBS CAPP) "Quantum-Limited Searches for High-Frequency Axion Dark Matter: CARAMEL and the Grenoble Initiative"

Tuesday 4 Aug 2026, 16:00 → 17:00 Asia/Seoul

Room B447-1 (Theory Bldg, 4F)

Axions are compelling dark-matter candidates, but searches at higher axion masses—and therefore higher microwave frequencies—become increasingly difficult. Conventional resonant cavities lose effective volume as the frequency increases, while quantum noise places progressively stricter demands on the receiver. New experimental concepts are therefore required to extend sensitive searches into the largely unexplored region above 10 GHz.

In this talk, I will present CARAMEL, a coherent detection approach designed to provide quantum-noise-limited sensitivity over a comparatively broad bandwidth. I will discuss its operating principles, expected performance, and potential advantages for high-frequency axion searches. I will then describe a new European-centered experimental initiative based in Grenoble that aims to combine CARAMEL with large-volume, high-field magnets and complementary detector geometries. The proposed program includes arrays of high-quality-factor resonators for the 10–30 GHz region and scalable antenna and dielectric structures for extending the search toward 30–100 GHz. The scientific reach, principal technical challenges, and opportunities for collaboration will also be discussed.