Fig. 2
From: Controlling the coherence of a diamond spin qubit through its strain environment
Strain-tuning of the SiV− energy levels. a Strain response of a transverse-orientation SiV− as shown in Fig. 1c. Wavelengths of the four optical transitions A, B, C, and D are recorded against strain. Raw PLE data with applied voltages can be found in Supplementary Fig. 7. The lower panel shows orbital splittings within GS (solid green squares) and ES (open blue circles) extracted from the optical transition wavelengths. Solid curves are fits to group theory-based strain response model.27, 29 b Thermal relaxation rates between GS orbital branches vs. their energy splitting. Error bars represent standard deviation of the estimated rate, and are under 5% for all data points. Fit to model in Supplementary Discussion allows extraction of the phonon-absorption rate γup and phonon-emission rate γdown. c Calculated phonon-absorption rate γup(Δgs) (solid yellow line) as a function of GS-orbital splitting Δgs at temperature T = 4 K. Left y-axis indicates the magnitude of this rate normalized to the value at zero strain, γup(46 GHz). Right y-axis indicates the two competing factors whose product determines γup: the phonon density of states (normalized to its value at zero strain), shown with the solid violet line, and the thermal occupation of acoustic modes shown with the dashed violet line
