Diamond defect-based sensing of programmably patterned molecular spin arrays with single-spin sensitivity*

The assembly of solid-state spins with controlled nanoscale spatial precision is an outstanding challenge in quantum technologies. Here we combine a DNA-based patterning technique with nitrogen-vacancy (NV) quantum sensors in diamond to sense 2D arrays of molecular spins programmably patterned via a monolayer of DNA origami on a diamond surface. We control the spacing of chelated Gd³⁺ spins down to 6 nm precision and verify this control by observing a linear relationship between proximal NVs’ T₁ relaxation rate, and the designated number of Gd³⁺ spins per origami unit. We confirm the preservation of the charge state and spin coherence of the proximal, shallow NV centers and discuss ongoing work towards probing ordered, strongly interacting 2D spin networks on the diamond surface.