Diamond magnetometer enhanced by ferrite flux concentrators
Diamond magnetometer enhanced by ferrite flux concentrators
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DOI：
10.1103/physrevresearch.2.023394
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发表时间：
2020-06-24
影响因子：
4.2
通讯作者：
Acosta, Victor M.
中科院分区：
文献类型：
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作者：
Fescenko, Ilja;Jarmola, Andrey;Acosta, Victor M.
基于金刚石中氮空位（NV）中心的磁强计是一种很有前途的室温固态传感器。然而，它们对低频磁场（小于或类似于1 kHz）的灵敏度目前大于或类似于10 pT s（1/2），排除了在医学成像、地球科学和导航中的潜在应用。在这里，我们表明，高磁导率的磁通量集中器，收集磁通量从一个更大的区域，并集中到金刚石传感器，可以用来提高金刚石磁力计的灵敏度。通过将NV掺杂的金刚石膜以蝴蝶结配置插入两个铁氧体锥体之间，我们实现了金刚石内的磁场振幅的类似250倍的增加。我们证明了类似的0.9 pT s（1/2）的磁场在10和1000 Hz之间的频率范围内的灵敏度。这是使用双共振调制技术来实现的，以抑制NV自旋能级的热位移的影响。磁力计使用200 mW的激光功率和20 mW的微波功率。本工作引入了一个新的自由度的金刚石传感器的设计，通过使用结构化的磁性材料来操纵磁场。
Magnetometers based on nitrogen-vacancy (NV) centers in diamond are promising room-temperature, solid-state sensors. However, their reported sensitivity to magnetic fields at low frequencies (less than or similar to 1 kHz) is presently greater than or similar to 10 pT s(1/2), precluding potential applications in medical imaging, geoscience, and navigation. Here we show that high-permeability magnetic flux concentrators, which collect magnetic flux from a larger area and concentrate it into the diamond sensor, can be used to improve the sensitivity of diamond magnetometers. By inserting an NV-doped diamond membrane between two ferrite cones in a bowtie configuration, we realize a similar to 250-fold increase of the magnetic field amplitude within the diamond. We demonstrate a sensitivity of similar to 0.9 pT s(1/2) to magnetic fields in the frequency range between 10 and 1000 Hz. This is accomplished using a dual-resonance modulation technique to suppress the effect of thermal shifts of the NV spin levels. The magnetometer uses 200 mW of laser power and 20 mW of microwave power. This work introduces a new degree of freedom for the design of diamond sensors by using structured magnetic materials to manipulate magnetic fields.