Probing QCD axion dark matter with DMRadio-m$^3$

Dark Matter Radio Cubic Meter (DMRadio-m$^3$) is a next-generation axion detector which will achieve sensitivity to the QCD axion over more than 1.5 orders of magnitude in mass, from 20neV to 0.8$\mu$eV. This science range, corresponding to frequencies of 5-200 MHz, includes substantial coverage of the two benchmark QCD axion models (KSVZ and DFSZ). To achieve these results, the DMRadio-m$^3$ detector will have a volume of $\sim$1m$^3$, a magnetic field of $\sim4$T, and a resonator quality factor Q $\sim 10^6$. The large volume and high magnetic field required by this experiment generates unique challenges compared to previous DMRadio detectors. In this talk we will describe plans for the DMRadio-m$^3$ experiment with a focus on the pickup structure geometry. In particular, we will demonstrate that high quality factors for the resonator can be achieved with a physically large coaxial copper structure.