New Pulsed Dual-axis Alkali-metal-noble-gas Comagnetometer

Alkali-metal-noble-gas comagnetometers demonstrated high sensitivity to non-magnetic couplings from being in the spin-exchange relaxation free(SERF) regime, and suppressed sensitivity to magnetic field drifts. This prompted their employment as gyroscopes, and in probing axion dark matter, anomalous spin-mass and spin-spin interactions, and violations of CPT and Lorentz invariance. We report on the development of a new ⁸⁷Rb-²¹Ne comagnetometer with pulsed optical pumping. After each circularly polarized pump laser pulse, an off-resonance linearly polarized probe beam measures the projection of ⁸⁷Rb-spins along its axis in the dark. This transient signal is fitted to an exponentially damped sinusoid on top of an exponential decay to extract parameters of interest. With similar sensitivity and suppression of magnetic field compared to previous single-axis continuously pumped(CW) implementations, the pulsed comagnetometer exhibits additional advantages including dual-axis sensitivity, suppression of response to pump and probe beams' relative misalignment, and easy separation of various systematic effects. Thus it has the potential to reduce high 1/f noise that limited CW comagnetometers' performance. We discuss current limitations on the pulsed case and possible future improvements.