Atomic theory in the 21st century: breakthrough advances, new applications, and neural networks

Professor Walter Johnson was an extraordinary person and scientist. He pioneered the development of modern relativistic high-precision atomic theory for studies of fundamental physics and other applications. To honor his legacy, I will explore the remarkable progress in atomic theory over the past two decades, highlighting its numerous applications spurred by enhanced computational capabilities, including the development of atomic clocks, advances in fundamental physics, the study of ultracold atoms and quantum simulations, and contributions to astrophysics. The theory story intertwines with experimental breakthroughs in quantum control and the subsequent improvements in measurement precision. I will review recent developments, including large-scale high-performance computing, the transformation of research codes into widely accessible software, the open sharing of data through a community portal, and the application of machine learning in atomic theory.