In recent years, unshielded atomic systems have been attracting researchers’ attention, in which decoherence is one of the major problems, especially for high-precision measurements. The nonlinear Zeeman effect and magnetic field gradient are the main decoherence sources of atomic electron spin in the Earth-field range. Here, we propose a method to cancel out the two dominant broadening effects simultaneously by an all-optical dynamic decoupling approach based on Raman scattering in the ${}^{87}\mathrm{Rb}$ Zeeman sublevels. By adjusting the parameters of the Raman lasers, we realize spin control along an arbitrary direction. We analyze the state evolution of atomic spin under the Raman light-control sequence in detail. The results show that both the nonlinear Zeeman effect and magnetic field gradient can be significantly suppressed.

中文翻译：

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全光动态解耦对地场范围内电子自旋的相干保护

近年来，非屏蔽原子系统引起了研究人员的关注，其中退相干是主要问题之一，特别是对于高精度测量。非线性塞曼效应和磁场梯度是地球场范围内原子电子自旋的主要退相干源。在这里，我们提出了一种通过基于拉曼散射的全光动态去耦方法同时抵消两种主要展宽效应的方法。${}^{87}铷$塞曼子层次。通过调整拉曼激光器的参数，我们实现了任意方向的自旋控制。我们详细分析了拉曼光控序列下原子自旋的状态演化。结果表明，非线性塞曼效应和磁场梯度都可以得到显着抑制。