EQuAL Seminar: Zhiran Zhang

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

Nitrogen-vacancy (NV) centers in diamond are a prominent example of solid-state spin qubits for applications in quantum information. However, the assembly of solid-state spins, including NVs or auxiliary spins near the diamond surface, with a controlled nanoscale spatial precision is still an outstanding challenge. Consequently, the pathway towards scaling up quantum simulation and entanglement-enhanced sensing using NVs remains unclear. In this presentation, I will present our recent progress, where we combine a DNA-based patterning technique with NV centers 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.