  MAGIS-100 is a next-generation instrument that uses light-pulse atom
interferometry to search for physics beyond the standard model, to be built and
installed at Fermilab. We propose to search for dark matter and new forces, and
to test quantum mechanics at new distance scales. The detector will use the
existing 100 m vertical NuMI access shaft to make it the world's longest
baseline atom interferometer. To maximize the sensitivity of the experiment, we
will use the latest advances in atomic clock technologies. The experiment will
be a significant step towards developing a 1000 m baseline detector, with
sufficient sensitivity to detect gravitational waves in the `mid-band' from 0.1
Hz - 10 Hz, between the Advanced LIGO and LISA experiments. Here we describe an
overview of the experiment and its physics reach.
