Quantum Optics Seminar by Justas Zalieckas

Pushing the limits: enhancing sensitivity with nitrogen-vacancy centers in diamond

Quantum sensing based on atomic-scale, negatively charged nitrogen-vacancy (NV) centers in diamond has gained immense interest for pushing the limits of analytical sensitivity and spatial resolution. In this talk, we present three advanced case studies that explore these boundaries across molecular, fluidic, and mechanical domains. First, we introduce a novel modality for detecting microRNAs by probing magnetic noise from paramagnetic Mn ions. Molecular dynamics simulations and experiments confirm enhanced Mn accumulation near the diamond surface, boosting spin relaxation contrast toward a sensitivity of ~23 microRNAs. Second, we present a non-invasive, multiparametric liquid analysis concept utilizing NV magnetometry, relaxometry, and DNA-tethered magnetic nanoparticles (MNPs). DNA–MNP complexes act as nanoscale mechanical oscillators whose thermally driven motion couples to near-surface NV centers, enabling a complex liquid to be mapped onto a high-dimensional quantum response vector via spatial surface patterning. Third, we investigate an atomic-impact sensor consisting of a graphene membrane suspended over a nanoscale aperture and functionalized with fluorescent nanodiamonds. We develop a model that links atomic momentum transfer and out-of-plane mechanical motion to optical transduction.