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Atomic magnetometer with microfabricated vapor cells based on coherent population trapping 下载免费PDF全文
An atomic magnetometer based on coherent population trapping(CPT) resonances in microfabricated vapor cells is demonstrated. Fabricated by the micro-electro-mechanical-system(MEMS) technology, the cells are filled with Rb and Ne at a controlled pressure. An experimental apparatus is built for characterizing properties of microfabricated vapor cells via the CPT effects. The typical CPT linewidth is measured to be about 3 k Hz(1.46 k Hz with approximately zero laser intensity) for the rubidium D1 line at about 90℃. The effects of pressure, temperature and laser intensity on CPT linewidth are studied experimentally. A closed-loop atomic magnetometer is finally finished with a sensitivity of 210.5 p T/Hz1/2 at 1 Hz bandwidth. This work paves the way for developing an integrated chip-scale atomic magnetometer in the future. 相似文献
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本文回顾了超导体上临界场强度 H c2 和不可逆场强度 Hirr 的相关物理背景及定义, 汇总了不同测量技术的原理和方法, 以及影响测量不确定度的主要因素, 指出 H c2 和 Hirr 测量的根本区别在于前者不应在测量中引入磁通运动相关的能量损耗. 分析了 H c2 和 Hirr 测量的难点, 介绍了以往国际上对建立单一测量方法标准所做的努力, 总结归纳了不同方法测量结果不一致的根本原因, 在于测量条件决定的测量分辨率以及人为设定的不同判据.因此如果可以精确控制测量条件和判据, 四引线电阻法最简便因而最适宜选做标准化的测量方法. 考虑到高场强磁体在国内实验室的普及程度, 现阶段有可能实现标准化的只有液氦冷剂浸泡下变磁场测量 Nb-Ti 复合超导线的J c 从而确定 Hirr(4.2 K) 相似文献
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