Precisely Mapping the Absolute Magnetic Field in Vacuum by an Optical Ramsey Atom Interferometer

Xiao-Bing Deng, Yao-Yao Xu, Xiao-Chun Duan, and Zhong-Kun Hu

Abstract：Atoms in magnetically sensitive sublevels constitute a natural sensor for absolute magnetic field measurements, which are explored here to form an optical Ramsey interferometer for determining the magnetic field distribution. An optical Ramsey atom interferometer provides a convenient way to map a magnetic field in vacuum. In comparison with the often used Raman spectroscopy method, a Ramsey interferometer can not only improve the sensitivity, but also dramatically suppress the contribution of the ac Stark effect. Furthermore, in this work, the magnetically sensitive atoms are velocity-selected, which improves the spatial resolution for the magnetometer as well as the contrast of the Ramsey fringes. A short-term sensitivity of 1.4nT/Hz^1/2 for magnetic field measurement is finally achieved even with an interrogation time as short as 500μs. The presented approach for absolute magnetic field measurement is expected to find wide applications in atom-interferometry-based precision measurements.

期刊名：Physical Review Applied

期/卷：15

页码：054062

发表时间：27 May 2021

DOI: https://doi.org/10.1103/PhysRevApplied.15.054062