Spin-Exchange-Relaxation-Free Magnetometry with Cs Vapor.

摘要

We describe a Cs atomic magnetometer operating in the spin-exchange-relaxation-free SERF regime. With a vapor cell temperature of 103 degrees C we achieve intrinsic magnetic resonance widths delta(B)=17 microG corresponding to an electron spin-relaxation rate of 300 s(exp 1) when the spin-exchange rate is Gamma(sub SE)=14 000 s(exp 1). We also observe an interesting narrowing effect due to diffusion. Signal-to-noise measurements yield a sensitivity of about400 pG/Hz. Based on photon shot noise, we project a sensitivity of 40 pG/(square root of Hz). A theoretical optimization of the magnetometer indicates sensitivities on the order of 2 pG/(square root of Hz) should be achievable in a 1cubic cm volume. Because Cs has a higher saturated vapor pressure than other alkali metals, SERF magnetometers using Cs atoms are particularly attractive in applications requiring lower temperatures.