Electronic structure calculations of defects in SiC and III-Nitrides
Title: Electronic structure calculations of defects in SiC and III-Nitrides
SNIC Project: SNIC 2019/3-667
Project Type: SNIC Medium Compute
Principal Investigator: Son Nguyen <son.tien.nguyen@liu.se>
Affiliation: Linköpings universitet
Duration: 2020-01-01 – 2021-01-01
Classification: 10304
Homepage: http://www.ifm.liu.se/materialphysics/semicond/
Keywords:

Abstract

Diamond, SiC, and III-Nitrides are promising materials for hosting solid state quantum bits realized by point defect electron and nuclear spins [D.J. Christle et al., Nature Materials 14, 160 (2015); M. Widmann et al., Nature Materials 14, 164 (2015)] and single photon emitters realized by bright light emitting single point defects to be used for quantum technologies and quantum sensing [J. R. Weber et al., PNAS 107, 8513-8518 (2010)]. Relying on ab initio methods, point defects’ electronic structure and properties can be calculated with high accuracy and directly compared with experimental measurements. These capabilities not only allow one to identify the atomic configuration of unknown point defects but also provide useful insight to the physics of applicable point defects. This project is a continuation of an on-going project, SNIC diary number SNIC 2018/3-625. First principles calculations carried out on SNIC computers in the last few years contributed to many of our articles. [V. Ivady et al. Nat. Commun. in press (arXiv:1905.11801), J. Davidsson et al. Appl. Phys. Lett.114 112107 (2019), M. Bockstedte et al., npj Quantum Mater. 3, 31 (2018), J. Davidsson et al., New J. Phys. 20, 023035 (2018), B. Magnusson et al., Phys. Rev. B 98, 195202 (2018), V. Ivády et al., Phys. Rev. B 96, 161114(R) (2017), D.J. Christle et al., Phys. Rev. X 7, 021046 (2017), K. Szász et al., Phys Rev. B 91 121201(R) (2015); A.L. Falk et al., Phys. Rev. Lett. 114, 247603 (2015); V. Ivády et al., Phys Rev. B 92, 115206 (2015)] In this project the electronic structure, zero-field splitting interaction, hyperfine interaction, electron-phonon interaction, and electrical and optical properties of magneto-optically active point defects in wide band gap semiconductors will be calculated within supercell formalism using density functional theory (DFT) hybrid functionals methods. The parameters obtained from calculations will be compared with experimental data observed by electrical and optical and magnetic resonance measurements carried out at Linköping University. We apply state-of-the-art hybrid density functional methods within large supercells (500-1500 atoms). We need to use large supercells to efficiently model single defects. The cost of the hybrid functional calculation is about an order of magnitude larger compared to standard methods. Such calculations require large CPU time and, therefore, we ask for 150000 CPU-core hours/month on Tetralith in 2020.