NV-Center Diamond Quantum Thermometer

A single nitrogen-vacancy defect in diamond carries a spin-1 electronic ground state whose zero-field splitting D shifts predictably with temperature. Sweeping a microwave field across the spin transition and reading out the diamond's fluorescence — optically detected magnetic resonance (ODMR) — produces a dip whose center tracks D(T). This simulator renders the actual diamond lattice around a real NV defect in 3D, lets you set a hidden true temperature and an external bias field, sweeps and averages a live ODMR spectrum, and fits the dip to recover a temperature estimate — showing exactly how averaging beats photon shot noise to reach the sub-degree precision real NV-diamond thermometers use for nanoscale thermal imaging.