First results from ABRACADABRA-10 cm: a search for Sub-eV axion dark matter

The axion is a promising dark matter candidate, which was originally proposed to solve the strong-CP problem in particle physics. To date, the available parameter space for axion and axion like particle dark matter is relatively unexplored, particularly at massesma ≲ 1 μeV.ABRACADABRAis a new experimental program to search for axion dark matter over a broad range of masses, 10−12 ≲ ma ≲ 10−6 eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to the QCD axion. In this Letter, we present the first results from a 1 month search for axions with ABRACADABRA-10 cm. We find no evidence for axionlike cosmic dark matter and set 95% C.L. upper limits on the axion-photon coupling between gaγγ < 1.4 × 10−10 and gaγγ < 3.3 × 10−9 GeV−1 over the mass range 3.1 × 10−10–8.3 × 10−9 eV. These results are competitive with the most stringent astrophysical constraints in this mass range.