Quantum Embedding Methods for Correlated Excited States of Point Defects

Explore quantum embedding methods for correlated excited states of point defects in a 52-minute lecture presented by Lukas Muechler from Penn State University. Delve into the challenges of describing excited electronic states of point defects and impurities, crucial for understanding materials properties and potential applications in quantum technologies. Learn about the implementation of an embedding approach based on Wannierization of defect orbitals and the constrained random-phase approximation. Examine case studies on three technologically relevant systems: a carbon dimer in hexagonal BN, the negatively charged nitrogen-vacancy center in diamond, and an Fe impurity in wurtzite AlN. Gain insights into the effects of DFT functionals, double-counting corrections, and challenges associated with determining energies and orderings of complex spin multiplets.