Real Time Vector Magnetometry with Quantum Diamond Sensor

The magnetic field is fundamental to numerous applications including medical diagnostic, chemical detection, and navigation. Nitrogen vacancy (NV) center in diamond has emerged as a promising quantum system for nanoscale magnetic field sensing, facilitated by a simple optical setup at ambient temperature. Despite advancements, real-time monitoring of the change in local magnetic field and precise determination of field directions remain challenging. Here, we present an approach to real-time vector magnetometry using NV center ensembles. Our system integrates an optical light guide, microwave control, and a graphical user interface (GUI) for controlling the pulse sequence and performing rapid optically detected magnetic resonance (ODMR) measurements. We observe zero-field splitting at 2.87 GHz and the Zeeman effect under external magnetic fields. Additionally, when the magnetic field orientation changes, we can observe multiple transitions from the different NV center axes, from which we can combine with a simulation to determine the vector magnetic field. Our system can be used as a basic quantum phenomena demonstration kit or in applications such as navigation or magnetic field imaging.