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Measurement of weak static magnetic field with nitrogen-vacancy color center

MetadataDetails
Publication Date2017-01-01
JournalActa Physica Sinica
AuthorsLi Lu-Si, LI Hong-hui, Zhou Li-li, YANG Zhi-Sheng, Ai Qing
Citations7

We propose a strategy to measure weak static magnetic fields with\nnitrogen-vacancy color center in diamond. Inspired by avian magnetoreception\nmodels, we consider the feasibility of utilizing quantum coherence phenomena to\nmeasure weak static magnetic fields. Nitrogen-vacancy (NV) color centers are\nregarded as the ideal platform to study quantum sciences as a result of its\nlong coherence time up to a millisecond timescale. In high-purity diamond,\nhyperfine interaction with 13C nuclear spins dominates the decoherence process.\nIn this paper, we numerically simulate the decoherence process between 0 and +1\nof the individual NV color center spin in 13C nuclear baths with various of\nmagnitudes of external magnetic fields. By applying Hahn echo into the system,\nwe obtain the coherence of NV color center spin as a function of total\nevolution time and magnetic field. Furthermore we obtain the high-accuracy\nrelationship between the three decoherence-characteristic timescales, i.e. T_W,\nT_R, T_2, and magnetic field B. And we draw a conclusion that T_R has the\nhighest sensitivity about magnetic field among the three time-scales. Thus, for\na certain NV color center, T_R can be the scale for the magnitude of magnetic\nfield, or rather, the component along the NV electronic spin axis. When\nmeasuring an unknown magnetic field, we adjust the NV axis to three mutually\northogonal directions respectively. By this means, we obtain the three\ncomponents of the magnetic field and thus the magnitude and direction of the\nactual magnetic field. The accuracy could reach 60 nT/Hz^{1/2},and could be\ngreatly improved by using an ensemble of NV color centers or diamond crystals\npurified with 12C atoms.\n