Many-body embedding for excited states of Fe in III-nitrides

ORAL

Abstract

A quantitative understanding of the electronic excited states of point defects in semiconductors and insulators is crucial for identifying defects detrimental to device performance, as well as those that have attractive properties for quantum applications. In particular, transition metal impurities in semiconductors have been widely studied in both contexts. One of the key limitations for a first-principles description of such systems is that transition mental excited states often involve correlated low-spin multiplets that require a multideterminant treatment. This is beyond the capabilities of density functional theory (DFT), which is the workhorse for computational studies of point defects. Using Fe in GaN and AlN as an example, we address this issue by treating the defect as a correlated subspace embedded in the lattice. The defect structure is obtained from hybrid-functional DFT calculations, and the subspace is isolated via Wannierization. The dielectric screening effects from the surrounding lattice to the local defect Coulomb interactions is accounted for using the constrained RPA approach. Finally, the many-body problem within the subspace is solved exactly. We compare our results to previous calculations using constrained DFT, and experimental measurements.

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Presenters

  • Cyrus Dreyer

    Columbia University, Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, 11794-3800, USA and Center for Computational Quantum Physics, Flatiron Institute, 162 5th, Department of Physics and Astronomy, Stony Brook University, State Univ of NY - Stony Brook, Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, 11794-3800, USA, and Center for Computational Quantum Physics, Flatiron Institute, 162 5th

Authors

  • Cyrus Dreyer

    Columbia University, Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, 11794-3800, USA and Center for Computational Quantum Physics, Flatiron Institute, 162 5th, Department of Physics and Astronomy, Stony Brook University, State Univ of NY - Stony Brook, Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, 11794-3800, USA, and Center for Computational Quantum Physics, Flatiron Institute, 162 5th

  • Lukas Muechler

    Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA, Center for Computational Quantum Physics, Flatiron Institute, Center for Computational Quantum Physics, The Flatiron Institute

  • Malte Roesner

    Radboud University, Institute for Molecules and Materials, Radboud University, Radboud University, Institute for Molecules & Materials, Heijendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands, Theory of Condensed Matter Department, Radboud University