Certain types of defects in solids - for example, an isolated impurity atom, or a vacancy where an atom is missing from the crystal - act like trapped molecules whose quantum-mechanical states can be controlled through use of light and electronics. Such defects are employed today as the basis for emerging applications in quantum information science, especially as single-photon sources, quantum memories, and quantum sensors. However, only a small number of potential defect systems, within a limited set of host materials, have been explored for this purpose, and those systems have specific properties that are not optimal for every application. Alternative defects, potentially occurring in materials that have been largely ignored, offer potential advantages, but the identification and development of new quantum defects has historically been a slow and arduous process. The goal of this DMREF project is to dramatically accelerate the discovery process for quantum defects in solids, by combining new computational and experimental techniques in an efficient paradigm inspired by the Materials Genome Initiative. The collaborating researchers will predict the basic properties of defects in a large number of materials, identify those systems best suited for the application at hand, fabricate and identify the target defects using high-throughput experimental methods, and establish their potential for applications in quantum science, especially as "spin-light interfaces" that will serve as the basis for future quantum networks. The research project will prepare multiple graduate and undergraduate students for future employment in the quantum workforce, and its outreach programs will introduce concepts of quantum science and technology to the general public through virtual and in-person activities.
Point defects in wide-bandgap semiconductors have emerged as leading platforms for quantum information science and technology, because they host isolated electron and nuclear spin states that can be addressed optically and electronically for use as qubits and quantum sensors. However, most research to date has concentrated on only a few defect systems and host materials, and the identification of new defect systems has been a slow, arduous, and generally ad hoc process. Given the vast number of potential materials and defect configurations, it remains a major challenge to theoretically predict and experimentally identify promising candidates in a systematic way. This collaborative DMREF project will address this challenge by combining new computational and experimental techniques to accelerate the discovery of defects, dopants, and host materials optimized for spin-light quantum interfaces. Computationally efficient analytic group theory-based models supported by judicious use of ab initio and low-energy numerical calculations will facilitate the systematic discovery of electronic systems with desired properties, while novel high-throughput single-emitter spectroscopy techniques will enable rapid experimental characterization. The immediate goal of the project is to identify previously unexplored spin systems that support coherent spin-photon interfaces at or near room temperature, using state-of-the art techniques for quantum dynamical control. More broadly, the ability to select defects that satisfy particular materials and application requirements will revolutionize solid-state quantum engineering and lead to diverse new applications of quantum science.
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.
