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HL: Fachverband Halbleiterphysik

HL 31: Focus Session: Frontiers of Electronic-Structure Theory V (joint session O/HL)

HL 31.2: Talk

Wednesday, March 29, 2023, 15:15–15:30, TRE Ma

Ab initio embedding approach for carbon defects in hexagonal boron nitride: A new platform to probe environmental screening — •Danis Badrtdinov¹, Magdalena Grzeszczyk², Alexander Hampel³, Cyrus Dreyer^3,4, Maciej Koperski², and Malte Rösner¹ — ¹Radboud University, Nijmegen, The Netherlands — ²National University of Singapore, Singapore — ³Flatiron Institute, USA — ⁴Stony Brook University, USA

Correlated defects in layered van der Waals hosts hold high promises for realizing quantum technologies, as they allow for various possibilities to control defect properties, e.g., via altering the host thickness or by changing the substrate material. A quantitative description of the defect ground and excited states taking the details of the impurity environment into account is, however, a considerable challenge for conventional density-functional theory (DFT) based methods as the impurities might be correlated and dielectric environmental screening is not fully accounted for in DFT. To tackle these challenges we apply and extend an embedding approach that treat the defect states within exact many-body theory, while DFT is used as a starting point to describe the bulk host material. We study various carbon defects embedded in hexagonal boron nitride (hBN), allowing us to disentangle all mechanisms responsible for the alteration of defect properties including modifications to the impurity structure and changes in the environmental screening upon thinning down the hBN host. Our new embedding approach paves the way for improved identification of defects in layered materials and to tailor their properties.