Dynamics of Rb and 21Ne spin ensembles interacting by spin exchange with a high Rb magnetic field

We report on the dynamics of spin-polarized Rb and Ne-21 ensembles in which the Ne-21 spin ensemble in a glass vapor cell experiences a high magnetic field produced by a Rb electron-spin ensemble. The coupled spin ensembles are modeled and the response of the transverse-step magnetic field excitation is solved and studied experimentally. Moreover, we analyze the frequency response of the ensembles to a transverse-oscillating magnetic field. We demonstrate the strong transverse damping and large frequency shift of the Ne-21 spin ensemble as the precession frequencies of Ne-21 spin and Rb spin match and the magnetic resonance spectroscopies of the two ensembles merge into one. We also demonstrate the operation of the spin ensembles as a self-compensating co-magnetometer that is insensitive to low-frequency magnetic fields that would be useful for rotation rate sensing. For such sensing applications, a large Rb density is achieved to polarize the Ne-21 spins. This density leads to a high Rb electron spin magnetic field and we demonstrate its effect on the dynamics of the co-magnetometer.