Density-Functional Theory (DFT) has seen tremendous improvements in the accuracy of its implementations since its first inception. The theory is characterized by the Nobel Prize-winning insight that the number density of electrons uniquely determines the ground-state properties of a system of atoms without the need to evaluate the many-body wavefunction for the electrons. In this talk, I will discuss another key insight that when coupled to DFT, leads to exceptionally accurate predictions from first principles. The insight is that the Fermi level (the electronic chemical potential) behaves in some cases as a manifestly local quantity rather than as uniform throughout a crystal sample, an assumption commonly employed in materials computations. This insight can be used to accurately predict the measured values of electric fields probed using color centers in diamond with the aim of improving the functioning of semiconductor devices. The insight can also be used to accurately determine timescales for charge-state decay of ionized color centers in diamond with applications in quantum computation, quantum communication, and quantum sensing.

Rodrick Kuate Defo is an assistant professor in the Department of Electrical Engineering and Computer Science at Syracuse University. Prior to his current position, he was a postdoctoral research fellow in the Department of Electrical and Computer Engineering and a Visiting Faculty Fellow in the McGraw Center for Teaching and Learning at Princeton University. He completed his PhD in physics with a secondary field in computational science and engineering at Harvard University and earned his bachelor's degree in math and physics from McGill University.