  The QCD axion is one of the most compelling candidates to explain the dark
matter abundance of the universe. With its extremely small mass ($\ll
1\,\mathrm{eV}/c^2$), axion dark matter interacts as a classical field rather
than a particle. Its coupling to photons leads to a modification of Maxwell's
equations that can be measured with extremely sensitive readout circuits.
DMRadio-m$^3$ is a next-generation search for axion dark matter below
$1\,\mu$eV using a $>4$ T static magnetic field, a coaxial inductive pickup, a
tunable LC resonator, and a DC-SQUID readout. It is designed to search for QCD
axion dark matter over the range $20\,\mathrm{neV}\lesssim m_ac^2\lesssim
800\,\mathrm{neV}$ ($5\,\mathrm{MHz}<\nu<200\,\mathrm{MHz}$). The primary
science goal aims to achieve DFSZ sensitivity above $m_ac^2\approx 120$ neV (30
MHz), with a secondary science goal of probing KSVZ axions down to
$m_ac^2\approx40\,\mathrm{neV}$ (10 MHz).
