Deployable sensors based on spins driven far-from-equilibrium

I will present our experiments leveraging electron and nuclear spins out of equilibrium to build highly sensitive, deployable, chemical sensors. These sensors utilize solid-state systems, such as semiconductors, where nuclear spins can be optically “hyperpolarized” to levels thousands of times greater than thermal equilibrium. Remarkably, these nuclei also exhibit extended coherence lifetimes (T2’>800 seconds), enabling their use in a range of applications. These include serving as highly sensitive quantum sensors for detecting time-varying magnetic fields, enhanced imaging agents, and for creating optically rewritable, nanometer-scale spin textures. They also provide a novel platform for exploring new physics far from equilibrium.

By incorporating them in nanoparticle form, we demonstrate the versatility of these sensors, deploying them in diverse environments such as manufactured materials, single-cells, living plants, and in flowing microdroplet emulsions. In these dynamic settings, we show the potential for highly sensitive chemical assays, outperforming the current state of the art. Finally, we show the ability to extend this approach to a broad class of materials, including defects in semiconductors and molecules containing rare-earth ions or photoexcited triplet electrons. This opens new avenues for sensor construction harnessing chemical synthesis, and expands possibilities for practical applications.

Speaker: Ashok Ajoy, UC Berkeley