Instrumentation for nuclear magnetic resonance in zero and ultra-low magnetic field

We review experimental techniques in our laboratory for nuclear magnetic resonance (NMR) in zero and ultralow magnetic field (below 0.1 uT) where detection is based on a low-cost, non-cryogenic, spin-exchange relaxation free 87Rb atomic magnetometer. The typical sensitivity is 20-30 fT/Hz^1/2 for signal frequencies below 1 kHz and NMR linewidths range from Hz all the way down to tens of mHz. These features enable precision measurements of chemically informative nuclear spin-spin couplings as well as nuclear spin precession in ultralow magnetic fields.