Quantum information science has the potential to revolutionize entire sectors of our economy, from computation, to sensing, to communications. Exciting early steps along this path include: i) the demonstration of arrays of quantum bits, "qubits", that can perform computational tasks and are on the verge of demonstrating the ability to outperform classical computers, ii) the development of nanoscale quantum sensors that allow for measurement of everything ranging from electric and magnetic fields to single photons, and iii) the development of "flying qubits" (tiny packets of light that travel through fiber optic cables) that are already enabling the implementation of quantum encryption that is un-hackable using current technology. The promise, however, rests on the development of systems that exhibit the exact quantum properties necessary to make a good computer, sensor, etc. Chemists have been manipulating atomic states for centuries in the design and synthesis of new molecules - making molecules prime candidates for the design of customized qubits and quantum systems. Early experiments have shown that this approach has promise, but the challenge is to get these molecules out of the beaker (so to speak) and onto a chip so that they can be connected to other supporting technologies. This project focuses on studying candidate molecules in these device-like environments, with the goal of learning the "design rules" for molecular quantum systems and designing new approaches to initialize and measure (write and read) quantum information. This work will take place in a collaborative network involving university scientists in the US and abroad as well as close contact with industrial partners interested in building the "quantum infrastructure" that will be necessary to support the emergence of quantum information sciences. This interdisciplinary environment will provide unique training opportunities for undergraduates, graduate students, and postdoctoral researchers in the development of a quantum workforce.
This project will develop a general framework for the integration of molecular spin-based qubits into solid state architectures, harnessing the ability to tune quantum states in molecular systems via synthetic control of ligand fields and electron-nuclear spin coupling to demonstrate a unique approach to generating qubits-by-design. Both electron and nuclear spin qubits have been demonstrated in molecular systems with appropriately engineered ligands. This performance is comparable to other leading qubit systems based on diamond NV centers, silicon donors, and Josephson junctions, and enables chemical tuning to tailor the coherence properties for particular applications. However, the field has thus far relied on measurements of large ensembles in solution, precluding the study of single-qubit properties and impeding scaling and integration with existing and emerging quantum technologies. Addressing this challenge requires an interdisciplinary program that exploits a framework of spin-dynamical theory and modeling to bridge from the synthesis of chemical qubits, to the validation of their quantum coherent properties, to the ultimate goal of quantum coherent device engineering. This project will explore how the requirements of quantum functionality intersect with the phase spaces accessible to molecular design and synthesis at one extreme and device design and fabrication at the other. As it matures, this framework will develop into a roadmap for the design of molecule-based quantum-functional devices that will be of broad relevance to the quantum information community and provide guidance as to how molecule-based quantum devices might be most effectively integrated into larger quantum-functional architectures.
This project is jointly funded by Quantum Leap Big Idea Program, the Division of Chemistry in the Mathematical and Physical Sciences Directorate, and the Office of International Science and Engineering.
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.
