Fig. 3: Long-term stability of the C-transition of SnV⁻ centres.

a Low excitation power of 0.5 nW long-term PLE in order to resolve spectral shifts caused by the charge environment or the 445 nm laser without initiating the charge cycle of the centre. The constantly charge stabilised emitter’s line position exhibits a standard deviation of less than 4(2) MHz over one hour of measurement. On the right, the integrated spectrum over all scans (black) with a width of 33(2) MHz is compared with the Fourier limited Lorentzian line (red, 25 MHz). b Long-term PLE on Emitter 2 with a power of 10 nW ensuring electron capture in every resonance scan while minimising power broadening. In the duration of one hour, the central resonance position exhibits a standard deviation of 10(2) MHz. The oscillations with a period of about 10 min in the central resonance position are related to the air conditioning cycle in our laboratory. On the right, the integrated spectrum over all scans (black) with a width of 103(2) MHz is compared to a Lorentzian that is only subject to power broadening (red) and exhibits a width of 88(2) MHz.