NV-Center Diamond Magnetometer

Nitrogen-vacancy (NV) centres in diamond are one of the most practical quantum sensor platforms in existence: a single electron spin, trapped in a crystal defect, that can be read out optically at room temperature. This simulator renders a small diamond lattice with a nitrogen-vacancy defect at its centre, fires a green pump laser at it, and sweeps a microwave field across the electron spin's 0→±1 transition. Off resonance the defect fluoresces brightly; on resonance the microwave field dumps population into a dark shelving state and fluorescence dips — the optically detected magnetic resonance (ODMR) signal every NV magnetometer is built around. Switching on an external magnetic field Zeeman-splits that single dip into two, and the splitting between them is a direct, calibration-free measurement of the field, exactly as it is in a real lab-grade NV magnetometer.