Structured light improves the sensitivity of SERF magnetometry via weak measurement

This Letter presents what we believe to be a novel approach to enhance the sensitivity of spin-exchange-relaxation-free (SERF) atomic magnetometry by integrating a structured light combined with weak measurement. This strategy may address the limitations of detecting minute transverse magnetic fields due to low signal-to-noise ratios (SNR). We employ a Laguerre-Gaussian (LG) beam with tunable topological charge to amplify magneto-optical rotation (MOR) signals via weak measurement. We find that under a fixed magnetic field, the output polarization rotation angle monotonically increases as a function of the topological charges l. Furthermore, we experimentally demonstrate a 1.5 times signal enhancement using LG beams compared with Gaussian beams, achieving much better sensitivity. The results pave way for applications of structured light in ultra-sensitive atomic magnetometry.