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内容記述 |
Magnetometry by using NV center, a localized coherent spin consisting of a pair of nitrogen atom and atomic void, in diamond is now regarded as a promising technique due to its potential for high sensitivity and miniaturization. The primary application for NV magnetometry was realized by optically detected magnetic resonance (ODMR). There have been plenty of reports on demonstration of magnetic sensing by using ODMR1. Towards simpler and more reliable implementation of NV magnetometry, photocurrent-detected magnetic resonance2 (PDMR) is one of the key technologies to bypass the bulky confocal optics that are necessary for ODMR-based photoluminescence detection. In a PDMR scheme, meanwhile, we use photocurrent to read out the NV spin state, which necessitates laser irradiation only for photoexcitation and spin initialization. The key for high sensitivity of PDMR-based magnetometry3 is low noise to spin-dependent signal ratio. For this sake, it is essential to mitigate the unwanted spin-independent photocurrent while maximizing the PDMR signal. In this study, we employed two different laser power and time4 in the pulse sequence to improve the signal to noise ratio5. As a result, the magnetic sensitivity as high as 13 nT/Hz0.5 was achieved. |
