Abstract
Nitrogen-vacancy (NV) centers in diamond can be used for nanoscale sensing with atomic resolution and sensitivity; however, it has been observed that their properties degrade as they approach the diamond surface. Here we report that in addition to degraded spin coherence, NV centers within nanometers of the surface can also exhibit decreased fluorescence contrast for optically detected electron spin resonance (OD-ESR). We demonstrate that this decreased OD-ESR contrast arises from charge state dynamics of the NV center, and that it is strongly surface-dependent, indicating that surface engineering will be critical for nanoscale sensing applications based on color centers in diamond.
Highlights
Nitrogen-vacancy (NV) centers in diamond are actively explored for a number of applications in quantum information processing and sensing because they exhibit long spin coherence times at room temperature, and their spin states can be optically initialized and read out with off-resonant excitation [1,2,3,4,5,6]
It has been well established that the diamond surface can host contaminants, magnetic defects, and electronic defects that give rise to noise, leading to short spin coherence times [7,8,9,10,11,12,13,14,15,16], and recent work has shown that careful preparation of the diamond surface can mitigate this noise, leading to extended spin coherence times [6,7,9]
In order to quantify the impact of charge state dynamics on optically detected electron spin resonance (OD-ESR) contrast, we focus on two diamond samples that contain shallow NV centers introduced by ion implantation, which exhibit distinctly different OD-ESR contrast and charge state behavior
Summary
Nitrogen-vacancy (NV) centers in diamond are actively explored for a number of applications in quantum information processing and sensing because they exhibit long spin coherence times at room temperature, and their spin states can be optically initialized and read out with off-resonant excitation [1,2,3,4,5,6]. Previous work has shown that charge state initialization can influence spin readout [27]; a detailed understanding of how these charge state dynamics can affect schemes for nanoscale sensing and its dependence on sample surface has not yet been established. In order to quantify the impact of charge state dynamics on OD-ESR contrast, we focus on two diamond samples (samples A and F) that contain shallow NV centers introduced by ion implantation, which exhibit distinctly different OD-ESR contrast and charge state behavior. We find that sample F exhibits charge state conversion rates that are comparable to the internal spin-dependent dynamics of the NV center, leading to decreased OD-ESR contrast. We use this comparison to quantify the impact of charge state conversion on CESR Both samples were prepared using nitrogen ion implantation followed by thermal annealing. We note that sample F is expected to have a shallower distribution of NV centers because of its lower implantation energy, the distribution of CESR is much lower than another sample that was prepared with the same ion implantation energy that does not exhibit surface contamination, sample B ( see Appendix A)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
