Neethirajan, Jeffrey NeethiHache, ToniPaone, DomenicoPinto, DineshDenisenko, AndrejStoehr, RainerUdvarhelyi, PeterPershin, AntonGali, AdamWrachtrup, JoergKern, KlausSingha, Aparajita2023-05-222023-05-222023-05-222023-03-1610.1021/acs.nanolett.2c04733https://infoscience.epfl.ch/handle/20.500.14299/197777WOS:000962516700001Near-surface negatively charged nitrogen vacancy (NV) centers hold excellent promise for nanoscale magnetic imaging and quantum sensing. However, they often experience charge-state instabilities, leading to strongly reduced fluorescence and NV coherence time, which negatively impact magnetic imaging sensitivity. This occurs even more severely at 4 K and ultrahigh vacuum (UHV, p = 2 x 10-10 mbar). We demonstrate that in situ adsorption of H2O on the diamond surface allows the partial recovery of the shallow NV sensors. Combining these with band-bending calculations, we conclude that controlled surface treat-ments are essential for implementing NV-based quantum sensing protocols under cryogenic UHV conditions.Chemistry, MultidisciplinaryChemistry, PhysicalNanoscience & NanotechnologyMaterials Science, MultidisciplinaryPhysics, AppliedPhysics, Condensed MatterChemistryScience & Technology - Other TopicsMaterials SciencePhysicsnv magnetometrysurface chemistryquantum sensingnanopillarlt-uhvodmrcolor-centersdiamondnanoscalespectroscopymagnetismtext::journal::journal article::research article