A subfemtotesla multichannel atomic magnetometer
A subfemtotesla multichannel atomic magnetometer
复制标题
DOI：
10.1038/nature01484
复制
发表时间：
2003-04-10
期刊：
影响因子：
64.8
通讯作者：
Romalis, MV
中科院分区：
文献类型：
--
作者：
Kominis, IK;Kornack, TW;Romalis, MV
磁场是最基本且普遍存在的物理可观测对象之一，它携带有关所有电磁现象的信息。在过去的30年里，在4K温度下工作的超导量子干涉器件（SQUIDs）作为超高灵敏度磁场探测器一直无可匹敌，其灵敏度可低至1飞特每赫兹的平方根（1飞特 = 10⁻¹⁵特斯拉）。例如，它们使绘制大脑产生的磁场以及定位潜在的电活动（脑磁图）成为可能。基于对光泵浦原子的拉莫尔自旋进动检测的原子磁力仪，在大测量体积下已接近类似的灵敏度水平，但在磁成像应用所需的更紧凑设计中灵敏度要低得多。原子磁力仪更高的灵敏度和空间分辨率以及非低温操作将使新的应用成为可能，包括无创绘制大脑皮层模块的可能性。在此我们描述一种新的无自旋交换弛豫（SERF）原子磁力仪，并展示了在仅0.3立方厘米的测量体积下达到0.54飞特每赫兹的平方根的磁场灵敏度。理论分析表明，该器件的基本灵敏度极限低于0.01飞特每赫兹的平方根。我们还展示了磁力仪的简单多通道操作以及分辨率为2毫米的磁场源定位。
The magnetic field is one of the most fundamental and ubiquitous physical observables, carrying information about all electromagnetic phenomena. For the past 30 years, superconducting quantum interference devices (SQUIDs) operating at 4 K have been unchallenged as ultrahigh-sensitivity magnetic field detectors(1), with a sensitivity reaching down to 1 fT Hz(-1/2) (1 fT = 10(-15) T). They have enabled, for example, mapping of the magnetic fields produced by the brain, and localization of the underlying electrical activity (magnetoencephalography). Atomic magnetometers, based on detection of Larmor spin precession of optically pumped atoms, have approached similar levels of sensitivity using large measurement volumes(2,3), but have much lower sensitivity in the more compact designs required for magnetic imaging applications(4). Higher sensitivity and spatial resolution combined with non-cryogenic operation of atomic magnetometers would enable new applications, including the possibility of mapping non-invasively the cortical modules in the brain. Here we describe a new spin-exchange relaxation-free ( SERF) atomic magnetometer, and demonstrate magnetic field sensitivity of 0.54 fT Hz(-1/2) with a measurement volume of only 0.3 cm(3). Theoretical analysis shows that fundamental sensitivity limits of this device are below 0.01 fT Hz(-1/2). We also demonstrate simple multichannel operation of the magnetometer, and localization of magnetic field sources with a resolution of 2 mm.