Dartmouth Events

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Meeting ID: 913 9744 0830
Passcode: 645291

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 was 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 was also 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. In addition to the many opportunities offered by the treatment of the Fermi level as a local quantity in materials theory and computation, I will discuss the ability of DFT to characterize properties and phenomena such as the hyperfine interaction for group-IV impurity-vacancy color centers in diamond.

Hosted by Professor Laura Ray.