AC Magnetic Field Sensing Using Continuous-Wave Optically Detected Magnetic Resonance of Nitrogen Vacancy Centers in Diamond

摘要

Nitrogen-vacancy (NV) centers in diamond are considered sensors for detectingmagnetic fields. Pulsed optically detected magnetic resonance (ODMR) istypically used to detect AC magnetic fields; however, this technique can onlybe implemented after careful calibration that involves aligning an externalstatic magnetic field, measuring continuous-wave (CW) ODMR, determining theRabi frequency, and setting the microwave phase. In contrast, CW-ODMR can besimply implemented by continuous application of green CW laser and a microwavefiled. In this letter, we report a method that uses NV centers and CW-ODMR todetect AC magnetic fields. Unlike conventional methods that use NV centers todetect AC magnetic fields, the proposed method requires neither a pulsesequence nor an externally applied DC magnetic field; this greatly simplifiesthe procedure and apparatus needed to implement this method. This methodprovides a sensitivity of 2.5 {\mu}T/Hz$^{1/2}$ at room temperature. Thus, thissimple alternative to existing AC magnetic field sensors paves the way for apractical and feasible quantum sensor.