Extended Data Fig. 3: Transition time in log-log plot of DEER spectra before and after the coherence enhancement.
From: Coherence enhancement of solid-state qubits by local manipulation of the electron spin bath
The DEER spectra of single NV demonstrated in the log-log plot showing the change of the transition time from ~21 μs to 64 μs before and after the charge manipulation. The coherence time was enhanced from 57 ± 3 μs up to 151 ± 5 μs. The dashed and dotted lines represent the powers of 2 and 2/3, respectively. In the model of configurational averaged surface spins, the transition time at which the DEER curve begins to demonstrate stretched exponential decay should be only sensitive to the depth of NV, regardless of the density of surface spins34. However, there should be subsurface electron spins such as P1 centre and charged vacancies induced by the ion implantation, which would also contribute to the decoherence and DEER signals of shallow NVs. Such subsurface spins may be located between the NV and the diamond surface, hence, the change of transition time indicates a changed distribution of the subsurface spins.
