Spin-Dependent Photocarrier Generation Dynamics in Electrically Detected Nitrogen-Vacancy-Based Quantum Sensor

Electrical detection of a nitrogen-vacancy (NV) center in diamond is advantageous for developing and integrating quantum information processing devices and quantum sensors. However, the mechanism for the electrical detection of NV spins is not fully understood. In this study, we observe positive contrast in photoelectrically detected magnetic resonance (PDMR) despite the usually observed negative PDMR contrast. To discuss the sign of the PDMR contrast, we numerically analyze the dynamics of photocarrier generation by NV centers using a seven-level rate model. It is found that the sign of the PDMR contrast depends on the difference in the photocurrent generated from the excited states and the metastable state of NV centers. Furthermore, we demonstrate alternating-current (AC) magnetic field sensing using spin coherence with the PDMR technique using a phase-cycling-based noise-canceling technique to suppress the noise from a fluctuating magnetic environment. We obtained the sensitivity of AC magnetic-field of ${\sim}29{\text{nT}}/\sqrt {{\mathbf{Hz}}} $ with the PDMR technique.