CAREER: Quantum Information Limits of Single-molecule Microscopy

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and co-funding from the Quantum Information Science Program in the Division of Physics, Professor Backlund's group at the University of Illinois Urbana-Champaign is combining theory and experiment to elucidate the “speed limits” that govern the measurement of molecular processes with light. Light-based chemical measurement and imaging is central to a vast array of technologies that find use both inside and outside of the laboratory, including in the areas of health, defense, and energy. This work guides the design of optimal measurement schemes, which in turn will enable the development of powerful new devices that might be used, for example, to improve disease diagnoses or detection of chemical weapons, or to enhance the efficiency of energy capture from light. In addition to these advancements in science and technology, the group seeks to broaden participation in, and understanding of, quantum information science (QIS) in disciplines beyond physics and communities beyond the university setting. The Backlund group seeks to theoretically establish and experimentally realize the fundamental precision bounds of single-molecule spectroscopy within the framework of quantum metrology. Their approach probes the limits to single-molecule measurement set by quantum parameter estimation and detection theory. Specific measurement tasks addressed include 1) assessing the limits of spatial resolution of non-photoswitching molecules, 2) discrimination of molecules based on the spectro-temporal properties of emission, and 3) assessing the fundamental limits to single-molecule chiroptical discrimination. Research efforts are complemented by educational initiatives that encourage undergraduate and graduate chemistry students to participate in QIS, and by broadening participation in QIS through engagement with the local community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.