Investigating the magnetic properties of helium-3

In a joint experimental-theoretical study published in Nature, physicists at the Heidelberg Max Planck Institute for Nuclear Physics (MPIK), together with collaborators from RIKEN, Japan, investigated the magnetic properties of the isotope helium-3. For the first time, the electronic and nuclear g-factors of the 3He+ ion were measured directly with a relative precision of 10–10. The electron-nucleus magnetic interaction (zero-field hyperfine splitting) was measured with an accuracy improved by two orders of magnitude. The g-factor of the bare 3He nucleus was determined via an accurate calculation of the electronic shielding. The results constitute the first direct calibration for 3He nuclear magnetic resonance (NMR) probes.