We spatially measured the spin-dephasing time (T2*) of nitrogen-vacancy centers around a single 45° mixed dislocation in a 12C-enriched diamond film. At distances greater than 2 μm from the dislocation core, T2* was approximately 3.5 μs, a value mainly limited by the electron spin bath of substitutional nitrogen. Within 2 μm of the core, however, T2* continuously decreased with proximity, reaching as low as 1 μs near the dislocation core. To understand this experimental result, we simulated the spatial profile of T2* using the elastic theory model with inhomogeneous stress field around the dislocation. This simulated profile was in good agreement with our experimental observations, confirming that the inhomogeneous stress field was the dominant source for T2* degradation near the dislocation.
Tsuji et al. (Mon,) studied this question.