  Zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) is an
alternative spectroscopic method to high-field NMR, in which samples are
studied in the absence of a large magnetic field. Unfortunately, there is a
large barrier to entry for many groups, because operating the optical
magnetometers needed for signal detection requires some expertise in atomic
physics and optics. Commercially available magnetometers offer a solution to
this problem. Here we describe a simple ZULF NMR configuration employing
commercial magnetometers, and demonstrate sufficient functionality to measure
samples with nuclear spins prepolarized in a permanent magnet or initialized
using parahydrogen. This opens the possibility for other groups to use ZULF
NMR, which provides a means to study complex materials without magnetic
susceptibility-induced line broadening, and to observe samples through
conductive materials.
