2023/08/21 by Santosh Ghimire, Ghimire, Santosh, Seong-Joo Lee +5
Earth and Planetary Sciences · Materials Science · #Diamond and Carbon-based Materials Research #Electronic and Structural Properties of Oxides #FOS: Physical sciences #High-pressure geophysics and materials #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2308.10437
openalex publication_date 2023/08/21 · openalex created_date 2023/08/23 · openalex updated_date 2026/07/28
The nitrogen-vacancy (NV) centers in diamond have ability to sense alternating-current (AC) magnetic fields with high spatial resolution. However, the frequency range of AC sensing protocols based on dynamical decoupling (DD) sequences has not been thoroughly explored experimentally. In this work, we aimed to determine the sensitivity of ac magnetic field as a function of frequency using sequential readout method. The upper limit at high frequency is clearly determined by Rabi frequency, in line with the expected effect of finite DD-pulse width. In contrast, the lower frequency limit is primarily governed by the duration of optical repolarization rather than the decoherence time (T2) of NV spins. This becomes particularly crucial when the repetition (dwell) time of the sequential readout is fixed to maintain the acquisition bandwidth. The equation we provide successfully describes the tendency in the frequency dependence. In addition, at the near-optimal frequency of 1 MHz, we reached a maximum sensitivity of 229 pT/√(Hz) by employing the XY4-(4) DD sequence.