Manufacturing of Color Centers in Hexagonal Boron Nitride for Quantum Applications

Creating defects in advanced materials can alter the materials' structure and enable them to perform in unique ways when exposed to light. These defects, called color centers, can interact with light and serve as important building blocks for the development of quantum computing, which can enable significant advances in artificial intelligence and machine learning, cybersecurity, new materials development and improvement of weather forecasting. This award supports fundamental research to provide needed knowledge for manufacturing these unique materials. The results from this research will benefit the US economy and society. The integrated educational program of the project will disseminate the research activities to a broad community of students and teachers at the high school, undergraduate, and graduate levels. These initiatives aim to increase the skilled workforce of engineers with improved participation from underrepresented American populations. This project aims to develop a laser-induced non-equilibrium process that will enable the formation of desired solid state defects that can function as color centers in 2D-hBN and offer the controlled tunability of single photon emitters in the visible spectrum. The study will first identify the processing conditions necessary for creating color centers in hBN by high-throughput screening. Optical microscopy, atomic force microscopy and scanning electron microscopy will then be used to characterize the 2D layer morphology and Raman spectroscopy will be used in combination to confirm the formation of hBN. Based on these findings, (i) machine learning-assisted atomic-resolution imaging of the defects using scanning transmission electron microscopy will be performed to identify the atomic arrangement at the defect sites, (ii) atomic-resolution core-loss electron energy-loss spectroscopy studies will be performed to investigate the electronic states at the defect sites and to correlate these electronic states with the atomic structure. Rutherford backscattering spectrometry will be used to obtain overall stoichiometry, elemental area density and impurity distribution. Photoluminescence spectroscopy will then be used to quantify the photonic response of the material and develop an understanding of the relationship of the atomic structure to this photonic response. The scientific outcomes of this study will contribute to advancing fundamental knowledge of the creation and optical performance of color centers in hBN and their qualification to demonstrate single photon emission. 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.