Linear and nonlinear coherence transfer of resonant nuclear-spin-dressed effect via metastability-exchange collisions

We present a systematic analysis to explain the observed magnetic resonance spectrum with three or five peaks spaced at Rabi frequency when the metastable ³He atoms are probed with a transverse circularly or linearly polarized 1083 nm laser beam, respectively. The resonance signals are generated in the ground state of ³He atoms, dressed by a resonant magnetic field, and transferred to the metastable state by collisions. The triplet spectrum is thought to be the result of the linear coupling between the metastable state and the ground state, while the quintuplet is thought to be that of the nonlinear coupling, and indicates that higher-order atomic polarization is created during the atomic collisions. More features of the magnetic resonance signals are investigated. (paper)