A steady-state spectral method to fit microwave absorptions of NV centers in diamonds: application to sensitive magnetic field sensing

Abstract

As one of the most promising candidates of solid-state qubits, nitrogen-vacancy (NV) centers in diamonds have been paid much attention for experimental quantum information processings, such as their energy level structures characterized by microwave absorption probes. In this paper we develop a simplified steady-state spectral method to exactly solve the driven three-level atomic system for fitting the measured microwave absorptions of the NV centers in diamonds. Due to the energy level structures of the NV centers in diamonds which are controllable by applying external magnetic fields, the precision measurements of the ESR spectra of the NV centers in diamond can be used to precisely detect the applied magnetic fields with nanometer spatial scale resolutions. Our steady-state spectral simulations show that the Bz-component (parallel with the axis of the NV centers) of the applied magnetic fields causes the symmetric Zeeman shifts in the zero-field splitting levels, while the B⊥-component (perpendicular to the NV axis mainly) causes the asymmetric Zeeman shifts. Therefore, by exactly probing the steady-state Zeeman shift absorption spectra of the NV centers in diamonds the applied magnetic fields can be detected precisely, at least theoretically.