论文标题
纳秒分辨的原子氢磁力计
A Nanosecond-Resolved Atomic Hydrogen Magnetometer
论文作者
论文摘要
自旋极化原子集合可以用于精确测量磁场。常规的原子磁力计表现出很高的灵敏度，尽管在低检测带宽处，从根本上受到原子的Larmor进动频率的限制。在这里，我们介绍了一种新型的原子磁力计，可以通过高时间分辨率实现敏感检测。磁力计基于监测磁场对由氯化氢（HCL）快速光解共解产生的自旋偏振原子的超精细相干的影响。该方案将磁性测量带宽扩展到由超精细相互作用设定的上限限制。将HCl用作极化原子的来源允许在$ 10^{19} $ - $ 10^{20} cm^{ - 3} $的范围内，比传统碱性原子仪的数量级高许多数量级。小于100μm的自旋投射噪声限制磁力计可以用纳秒时间分辨率检测到低至1 nt的磁场。这种新型磁力计为精确测量超快磁场提供了新的可能性，并在生物学，表面科学和化学中应用。
Spin polarized atomic ensembles can be used for the precise measurement of magnetic field. Conventional atomic magnetometers have demonstrated high sensitivities, albeit at low detection bandwidth, fundamentally limited by the Larmor precession frequency of the atoms. Here, we introduce a new type of atomic magnetometer which can realize sensitive detection with high temporal resolution. The magnetometer is based on monitoring the effect of the magnetic field on the hyperfine coherences of spin-polarized hydrogen atoms produced from the rapid photodissociation of hydrogen chloride (HCl). This scheme extends the magnetic measurement bandwidth to an upper frequency limit set by the hyperfine interaction. The use of HCl as the source for polarized atoms allows for large spin densities in the range of $10^{19}$ - $10^{20} cm^{-3}$, many orders of magnitude higher than those achieved with conventional alkali-atomic magnetometers. A spin-projection noise-limited magnetometer smaller than 100 μm can detect with nanosecond temporal resolution a magnetic field as low as 1 nT. This novel magnetometer opens new possibilities for precise measurement of ultrafast magnetic fields, with applications in biology, surface science and chemistry.
