Towards enhanced performance of SERF atomic magnetometers: a DFT study on the anti-relaxation mechanism
Haoran Xu, Yi-an Xu, Yuan Hu +3 more
Anti-relaxation coatings are commonly employed in the alkali metal vapor cells of spin-exchange relaxation-free (SERF) atomic magnetometers, as they can prevent spin depolarization of alkali metal atoms. However, the anti-relaxation mechanism and the interaction process between atoms and coatings remain unclear. This lack of understanding hinders the further improvement of the performance of SERF atomic magnetometers. In this study, we employed first-principles density functional theory to comparatively investigate the microscopic interactions between Rb atoms and SiO2 substrates as well as three commonly used organic coatings. The adsorption energies and valence electron loss of Rb atoms during their adsorption processes on these coated surfaces were systematically calculated. It was found that the Rb atoms exhibited the lowest adsorption energy and the highest charge transfer on the SiO2 surface, with values of –3.55eV and 0.90 |e|, respectively. In contrast, on the 1-nonadecene surface, the adsorption energy reached only –0.13eV, with a charge transfer of merely 0.14 |e|. Similar results were observed for other organic coatings and these findings are highly consistent with previous anti-relaxation performance tests, indicating that alkali metal atoms undergo less energy dissipation and charge transfer on the surface of organic coatings, which can better maintain the electron spin polarization state. A close relationship can be established between adsorption energy, charge transfer and the anti-relaxation performance of coatings, which provides effective guidance for future theoretical research and material selection, thus accelerating the development of SERF magnetometers.
Sixth Symposium on Novel Optoelectronic Detection Technology and Applications•May 11, 2026•0 citations