Abstract Measurement of extremely weak magnetic fields in double-resonance atomic magnetometers based on resonant optical excitation has been an active area of research in recent years. Magnetometer sensitivity can be improved via detection of higher harmonics of the magnetic resonance, a resonance which has a maximum sensitivity under conditions where the ratio of the amplitude to the line-width of the resonance signal is maximized. Based on the Bloch theorem, we analyze the time evolution of the spin polarization corresponding to each harmonic component of the resonance signal and measure this progression experimentally. Our results revealed that there is an optimal harmonic number for achieving the highest sensitivity. We have shown that the longitudinal and transverse relaxation times of spin polarization can manipulate the harmonics with the best sensitivity while the excitation frequency is detuned from the Larmor frequency.

中文翻译：

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高灵敏度 Mx 磁力计中光学检测磁共振谐波的弛豫时间依赖性

摘要 近年来，基于共振光激发的双共振原子磁强计中极弱磁场的测量一直是一个活跃的研究领域。磁力计的灵敏度可以通过检测磁共振的高次谐波来提高，这种谐振在共振信号的振幅与线宽的比率最大化的条件下具有最大的灵敏度。基于布洛赫定理，我们分析了与共振信号的每个谐波分量相对应的自旋极化的时间演化，并通过实验测量了这种进展。我们的结果表明，存在实现最高灵敏度的最佳谐波数。