Surface ‘dirt’ shields quantum sensors from noise

Researchers at Princeton University and the University of Iowa discovered a counterintuitive effect impacting nanoscale quantum sensors. The team observed approximately a four-fold reduction in coherence time for shallow nitrogen-vacancy (NV) centers in diamond when transitioning from ambient conditions to ultrahigh vacuum. This finding challenges the long-held assumption that surface contaminants are the primary cause of decoherence in these sensors. The work highlights a complex role for surface adsorbates in shaping the noise environment of shallow NV centers, with important implications for nanoscale quantum sensing. This counterintuitive result upends expectations that removing surface contaminants would improve the performance of these nanoscale quantum sensors, instead revealing a more complex interplay between the diamond surface and its environment. Researchers directly compared the behavior of individual NV centers in both environments, tracking their locations to ensure a one-to-one assessment of the surface’s impact on their quantum properties. The study tested a long-held assumption that surface adsorbates contribute significantly to…