Quantum embedding methods for correlated excited states of point defects: Case studies and challenges
| Autor: | Lukas Muechler, Danis I. Badrtdinov, Alexander Hampel, Jennifer Cano, Malte Rösner, Cyrus E. Dreyer |
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| Rok vydání: | 2022 |
| Předmět: |
EMBEDDING METHOD
EXCITED ELECTRONIC STATE Theory of Condensed Matter III-V SEMICONDUCTORS FOS: Physical sciences FREE ENERGY MATERIALS PROPERTIES DEFECT AND IMPURITIES QUANTUM TECHNOLOGIES DENSITY-FUNCTIONAL-THEORY ZINC SULFIDE DOUBLE COUNTING ALUMINUM NITRIDE DENSITY FUNCTIONAL THEORY Condensed Matter - Materials Science IMPURITIES EMBEDDINGS Materials Science (cond-mat.mtrl-sci) COMPUTATION THEORY QUANTITATIVE DESCRIPTION CASE-STUDIES DESIGN FOR TESTABILITY GROUND STATE EXCITED-STATES APPROXIMATION ALGORITHMS QUANTUM THEORY POINT DEFECTS |
| Zdroj: | Physical Review B Physical Review B, 105, 23, pp. 1-19 Physical Review B, 105, 1-19 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | A quantitative description of the excited electronic states of point defects and impurities is crucial for understanding materials properties, and possible applications of defects in quantum technologies. This is a considerable challenge for computational methods, since Kohn-Sham density-functional theory (DFT) is inherently a ground state theory, while higher-level methods are often too computationally expensive for defect systems. Recently, embedding approaches have been applied that treat defect states with many-body methods, while using DFT to describe the bulk host material. We implement such an embedding method, based on Wannierization of defect orbitals and the constrained random-phase approximation approach, and perform systematic characterization of the method for three distinct systems with current technological relevance: a carbon dimer replacing a B and N pair in bulk hexagonal BN (C$_{\text{B}}$C$_{\text{N}}$), the negatively charged nitrogen-vacancy center in diamond (NV$^-$), and an Fe impurity on the Al site in wurtzite AlN ($\text{Fe}_{\text{Al}}$). For C$_{\text{B}}$C$_{\text{N}}$ we show that the embedding approach gives many-body states in agreement with analytical results on the Hubbard dimer model, which allows us to elucidate the effects of the DFT functional and double-counting correction. For the NV$^-$ center, our method demonstrates good quantitative agreement with experiments for the zero-phonon line of the triplet-triplet transition. Finally, we illustrate challenges associated with this method for determining the energies and orderings of the complex spin multiplets in $\text{Fe}_{\text{Al}}$. Comment: 19 pages, 14 figures. Supplemental material: 7 pages |
| Databáze: | OpenAIRE |
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