Laser-magnetic-resonance detection of magnesium atoms in the metastable ^3P_0,1,2 states

Abstract

Transitions between fine-structure levels of the metastable (3s3p³P) state of magnesium have been observed by means of the highly sensitive technique of far-infrared laser-magnetic-resonance spectroscopy. The g factors for the ³P₁ and ³P₂ levels are 1.50111(16) and 1.50102(16), respectively, and the ³P₁–³P₂ energy separation is 1 220 575.1(33) MHz. The observed g factors show good agreement with the predicted values. This stands in marked contrast to similar results for atomic silicon (³P) and aluminum (²P), for which the theoretical and experimental g factors differ substantially. The value of the ³P₁–³P₂ energy separation is improved by nearly 2 orders of magnitude over the optical value and is of sufficient accuracy to permit possible extraterrestrial identification.