Integration of Nanoscale Materials for Quantum Sensing with Nitrogen-Vacancy Centers.

The nitrogen-vacancy (NV) color center in diamond is an established nanoscale quantum sensor able to detect the magnetic and electronic properties of low-dimensional materials, such as hBN, graphene, and thin metal films. However, integration of materials with the NV can have complex positive and negative consequences for sensing, due to the interaction between the target material and the sensor resulting in a reduction of NV spin lifetimes and photoluminescence rates. Further, metals and high work function materials can induce band bending and destabilize the charge environment resulting in the magnetically sensitive NV^- converting to a magnetically insensitive charge state, NV⁰. On the other hand, some of these complications can be turned into advantages, for instance the band bending caused by metals can deplete magnetic noise sources of electrons, increasing spin lifetime. In this talk, I will present our work integrating NV-rich diamond with quantum materials while maintaining or even enhancing the quality of NV sensors. We characterize a series of NV ensembles at variable depth influenced by band-bending metals deposited on the diamond to understand the optimal tradeoff between charge conversion and sensitivity.