  In this letter we point out the possibility to study new physics in the
neutrino sector using dark matter detectors based on liquid xenon. These are
characterized by very good spatial resolution and extremely low thresholds for
electron recoil energies. When combined with a radioactive $\nu_e$ source, both
features in combination allow for a very competitive sensitivity to neutrino
magnetic moments and sterile neutrino oscillations. We find that, for realistic
values of detector size and source strength, the bound on the neutrino magnetic
moment can be improved by an order of magnitude with respect to the present
value. Regarding sterile neutrino searches, we find that most of the gallium
anomaly could be explored at the 95% confidence level just using shape
information.
