Fig. 6: Pulse block diagram for experiments conducted with spin levels.

Under an applied magnetic field, two spin conserving transitions of the SnV become accessible. By tuning a CW laser to one of the transitions, and switching the laser on and off with AOMs it is possible to pump the population between the spin levels (initialize) and read how much of the population is thermalized back to the original state (readout). We histogram the detected photons using a time tagger in repeated measurements. The sequence starts with a charge state initialization pulse (blue, 445 nm) and continues with a spin initialization. After a variable delay, spin state is read out. Adding a SUPER pulse at the beginning of the delay and comparing the thermalization rates allows for probing additional spin mixing effects.