Digital magnetic heterostructures based on GaN using GGA-1/2 approach

Abstract

We present ab-initio calculations of seven digital magnetic heterostructures, GaN δ-doped with V, Cr, Mn, Fe, Co, Ni, and Cu, forming two-dimensional systems. Only GaN δ-doped with V or Cr present a ferromagnetic ground state with high Curie temperatures. For both, to better describe the electronic properties, we used the GGA-1/2 approach. The ground state of GaN/Cr resulted in a two dimensional half-metal, with 100% spin polarization. For GaN/V, we obtained an insulating state: integer magnetic moment of 2.0 μB, a minority spin gap of 3.0 eV close to the gap of GaN, but a majority spin gap of 0.34 eV.

Polytypism in ZnS, ZnSe, and ZnTe: First-principles study

“…This approach allows the inclusion of spin-orbit interaction in a rather easy manner, which usually works very well and gives very good results for the band gaps, bandwidths, and band dispersions [74][75][76][77][78][79][80][81]. In addition, it compares well with results of the GW quasiparticle (QP) approach [26,72,[82][83][84].…”

Limitations of the DFT–1/2 method for covalent semiconductors and transition-metal oxides

“…A study of the negatively charged nitrogen-vacancy center in diamond has been performed with a generalized version of DFT-1/2, which is suited not only for band gap but also optical transitions and defect levels. 28 Other applications include studies of doped materials, 29,30 heterostructures, 31,32 surfaces, 33,34 or interfaces. 35,36 Also, in a study of semiconducting indium alloys comparing the DFT-1/2 method with hybrid functionals, it was found that, although the hybrid functionals were slightly more accurate, DFT-1/2 allows for larger supercells and consequently better convergence of the bowing parameter.…”

Density Functional Theory Half-Electron Self-Energy Correction for Fast and Accurate Nonadiabatic Molecular Dynamics

“…The approaches can reproduce the experimental bandgaps of various semiconductors compared to hybrid functionals and GW without additional cost. For instance, the PBE-1/2 method produces a 3.04 eV bandgap of rutile TiO 2 , which is similar to values of 3.39 eV determined by HSE06 and 3.46 eV determined by G 0 W 0 . , In addition, this method can accurately describe the defective systems of GaN doping with a heteroatom or heterojunctions formed between TiO 2 and ZnO . The PBE-1/2 method combined with spin–orbit coupling (SOC) produces the bandgaps of metal halide perovskites and layered perovskites that are in excellent agreement with the experiments, which requires typically hybrid functionals or GW with SOC. , The success of the DFT-1/2 method in predicting bandgaps for a variety of materials motivates us to combine it with NA-MD because of the lack of reported literature to date, to perform a fast and accurate quantum dynamics calculation for condensed-phase materials at the nanoscale.…”