The proposed program seeks to develop techniques for local ultra-sensitive electric field measurements in biologically compatible conditions, using quantum metrology based on electron spin dynamics in the nitrogen vacancy center in diamond. While broad impact of such techniques is anticipated, the PI seeks one specific proof-of-concept application: real-time imaging of the electrical activity in large networks of neurons. The program targets scalable production techniques of high-purity diamond nanoprobes with application-driven design, and the application of such probes for high-speed, super-resolution wide-area microscopy technique with ultra-sensitive electric field detection. Research activities include material processing of diamond, optical microscopy, optically detected electron spin resonance measurements, and translation of such techniques to biological systems through extensive collaborations with neuroscientists.
Intellectual Merit: The proposed interdisciplinary research relies on the integration of techniques from semiconductor nanofabrication, spin physics in solids, and neuroscience. The PI seeks to show, for the first time, that electron spin-based sensing techniques could enable optical electric field imaging in living cells, and that imaging could be accomplished with a sub-wavelength spatial resolution. Improved electric field sensing technologies in the life sciences could enable profound advances. The proof-of-concept application real-time imaging of the electrical activity in large networks of neurons would represent a major new tool for neuroscience. Moreover, the techniques to be developed could also lead to new research capabilities in a large range of fields that benefit from high-precision optical electric field sensors. The PI seeks these advances through (i) massively parallel readout of more than 100 nitrogen vacancy center spins simultaneously with a 2D detector array, (ii) enhanced electric field detection using nitrogen vacancy centers in high-purity diamond probes with 100 × longer electron spin coherence than in currently available nanocrystals, and (iii) dynamic spin decoupling schemes to extend the spin coherence time. Initial work indicates that the spin-based probes appear to be sufficiently sensitive for optical measurements of neuronal electrical activity across networks of cells with sub-millisecond temporal resolution.
Broader Impact: The project will engage multiple student populations in physical sciences research, including 1-2 high school students, 1-2 undergraduate students, and 1-2 Massachusetts Institute of Technology graduate students. Students will have close interaction with research groups spanning electrical engineering, physics, biology, and neuroscience. Broader impact includes: (1) Integration of the research in a new course on quantum information and quantum metrology, and the dissemination of course and experimental projects through a website to other institutions interested in implementing some or all of the curriculum. (2) Effective outreach components through the Minority Introduction to Engineering and Science, in which graduate students and the PI will engage young researchers from underrepresented student populations; engagement of undergraduates through the Undergraduate Research Opportunities Program. (3) Dissemination of the research and educational components through the literature and conferences.
