An ab initio pseudopotential method based on density functional theory, generalized gradient corrections to exchange and correlation, projector-augmented waves is used investigate structural, energetical, electronic, optical properties of $\mathrm{MgO}$, $\mathrm{ZnO}$, $\mathrm{CdO}$ in rocksalt, cesium chloride, zinc blende, wurtzite structure. In the case $\mathrm{MgO}$ we also examine nickel arsenide structure a graphitic phase. The stability ground-state phases rocksalt...

Using quasiparticle band structures based on modern electronic-structure theory, we calculate the branch-point energies for zinc blende (GaN, InN), rocksalt (MgO, CdO), wurtzite (AlN, GaN, InN, ZnO), and rhombohedral crystals (In2O3). For CdO, ZnO, also In2O3 are located within lowest conduction band. These predictions in agreement with observations of surface electron accumulation (InN, CdO) or conducting behavior oxides (ZnO, In2O3). The results used to predict natural offsets materials...

The study of the oxygen vacancy ($F$ center) in MgO has been aggravated by fact that positively charged and neutral (${F}^{+}$ ${F}^{0}$, respectively) absorb at practically identical energies. Here we apply many-body perturbation theory ${G}_{0}{W}_{0}$ approximation Bethe-Salpeter approach to calculate optical absorption emission spectrum all three charge states. We observe unprecedented agreement between calculated experimental spectra for ${F}^{0}$ ${F}^{+}$ center. Our calculations...

The structural, electronic, and optical properties of the semiconducting oxide SnO${}_{2}$ are investigated using first-principles calculations. We employ ${G}_{0}{W}_{0}$ formalism based on hybrid-functional calculations to compute quasiparticle band structure density states for which we find good agreement with results from photoemission two-photon absorption experiments. also address open questions regarding ordering symmetries. In a second step use our electronic as starting point...

We compute optical properties including excitonic effects for the equilibrium polymorphs of three group-II metal monoxides by solving Bethe-Salpeter equation. The underlying electronic structures are based on results a recently developed $GW$ approach starting from hybrid exchange-correlation functional. resulting quasiparticle band discussed with respect to their mapping computationally less expensive computed using $\text{GGA}+U$ method together scissor operator $\ensuremath{\Delta}$....

The valence-band density of states single-crystalline rock-salt CdO(001), wurtzite $c$-plane ZnO, and rock- salt MgO(001) are investigated by high-resolution x-ray photoemission spectroscopy. A classic two-peak structure is observed in the VB-DOS due to anion $2p$-dominated valence bands. Good agreement found between experimental results quasi-particle-corrected density-functional theory calculations. Occupied shallow semicore $d$ levels CdO ZnO. While these exhibit similar spectral features...

We show that atomistic first-principles calculations based on real-time propagation within time-dependent density functional theory are capable of accurately describing electronic stopping light projectile atoms in metal hosts over a wide range velocities. In particular, we employ plane-wave pseudopotential scheme to solve Kohn-Sham equations for representative systems H and He projectiles crystalline aluminum. This approach simulate nonadiabatic electron-ion interaction provides an accurate...

Two-dimensional (2D) materials offer an ideal platform to study the strain fields induced by individual atomic defects, yet challenges associated with radiation damage have so far limited electron microscopy methods probe these atomic-scale fields. Here, we demonstrate approach single-atom defects sub-picometer precision in a monolayer 2D transition metal dichalcogenide, WSe2-2xTe2x. We utilize deep learning mine large data sets of aberration-corrected scanning transmission images locate and...

SnO is a promising oxide semiconductor that can be doped both p- and n-type, but the doping mechanisms remain poorly understood. Using hybrid functionals, we find native defects cannot account for unintentional p-type conductivity. Sn vacancies are shallow acceptors, they have high formation energies unlikely to form. Unintentional impurities offer more likely explanation doping; hydrogen candidate, it forms shallow-acceptor complexes with vacancies. We also demonstrate ambipolar behavior of...

Abstract Recent observations of switching magnetic domains in ferromagnetic metals by circularly polarized light, so-called all-optical helicity dependent switching, has renewed interest the physics that governs interactions between angular momentum photons and order parameter materials. Here we use time-resolved-vectorial measurements magnetization dynamics thin layers Fe, Ni Co driven picosecond duration pulses light. We decompose torques drive into field-like spin-transfer components...

Antiferromagnetic materials have recently gained renewed interest due to their possible use in spintronics technologies, where spin transport is the foundation of functionalities. In that respect, metallic antiferromagnets are particular since they enable complex interplays between electronic charge transport, spin, optical, and magnetization dynamics. Here, we review phenomena conductivity provides a unique perspective for practical fundamental properties antiferromagnetic materials. The...

Excitonic effects in optical spectra and electron-hole pair excitations are described by solutions of the Bethe-Salpeter equation (BSE) that accounts for Coulomb interaction excited pairs. Although computation excitonic an extended frequency range efficient methods available, determination analysis individual exciton states still requires diagonalization Hamiltonian $\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{H}$. We present a numerically approach calculation with quadratically scaling...

We have developed a computationally-tractable first-principles approach (based on density-functional and many-body perturbation theories) to treat the indirect absorption of light by free carriers in semiconductors insulators applied it technologically important class group-III nitrides. Indirect impurity-bound carriers, mediated electron-phonon, charged-defect, alloy scattering, is an loss mechanism which may explain origin observed nitride laser devices. The electron-phonon interaction...

Results for structural and elastic properties of wurtzite zinc-blende group-III nitrides are calculated using the recently developed AM05 exchange-correlation (XC) functional. They compared to calculations based on local-density approximation or generalized-gradient approximation. We find that provides a better agreement with experimental results. The atomic geometries used compute quasiparticle band structures within Hedin's $GW$ approximation, an initial electronic structure HSE hybrid XC...

Explicit integrators for real-time propagation of time-dependent Kohn-Sham equations are compared regarding their suitability performing large-scale simulations. Four algorithms implemented and assessed both stability accuracy within a plane-wave pseudopotential framework, employing the adiabatic approximation to exchange-correlation functional. Simulation results single sodium atom embedded in bulk magnesium oxide discussed. While first-order Euler scheme second-order finite-difference...

The role of surface termination on phonon-mediated relaxation an excited electron in quantum dots was investigated using first-principles simulations. terminations a silicon dot with hydrogen and fluorine atoms lead to distinctively different behaviors, the shows nontrivial process. confined electronic states are significantly affected by dot, we find that particular state dictates behavior through its infrequent coupling neighboring states. Dynamical fluctuation this results slow shuttling...

We use time-dependent density functional theory to study self-irradiated Si. calculate the electronic stopping power of Si in by evaluating energy transferred electrons per unit path length an ion kinetic from 1 eV 100 keV moving through host. Electronic is found be significant below threshold velocity normally identified with transitions across band gap. A structured crossover at low exists place a hard threshold. An analysis time dependence transition rates using coupled linear rate...

Soft x-ray emission and absorption spectroscopy of the $\text{O}\text{ }K$-edge are employed to investigate electronic structure wurtzite ZnO(0001). A quasiparticle band calculated within $GW$ approximation agrees well with data, most notably energetic location $\text{Zn}\text{ }3d--\text{O}\text{ }2p$ hybridized state anisotropy spectra. Dispersion in is mapped using coherent $\mathbf{k}$-selective part resonant We show that a more extensive mapping bands possible case crystalline such as found ZnO.

The electronic structure of well-ordered single-crystal thin films CdO(100) has been studied using angle-resolved photoemission spectroscopy. Quantized electron subbands are observed above the valence-band maximum. existence these states provides evidence an intrinsic accumulation space-charge layer near CdO surface, interpretation supported by coupled Poisson-Schr\"odinger calculations. origin result is discussed in terms bulk band calculated quasiparticle-corrected density-functional...

Abstract We use Hedin's GW framework to compute quasiparticle bands for group‐II monoxides in wurtzite ( wz ) structure. Modern hybrid density functional theory is applied the starting electronic structure solution of equation. derive band parameters and effective masses three uppermost valence as well lowest conduction including spin–orbit coupling. Optical transition matrix elements exciton binding energies are also calculated. In addition prediction ‐MgO ‐CdO we discuss chemical trend.

Electron doping turns semiconductors conductive even when they have wide fundamental band gaps. The degenerate electron gas in the lowest conduction-band states, e.g., of a transparent conducting oxide, drastically modifies Coulomb interaction between electrons and, hence, optical properties close to absorption edge. We describe these effects by developing an ab initio technique which captures also Pauli blocking and Fermi-edge singularity at optical-absorption onset, that occur addition...

Isostructural and heterostructural pseudobinary MgxZn1−xO CdxZn1−xO alloys are studied by combining the wurtzite rocksalt polymorphs within a cluster expansion. The computationally demanding calculation of quasiparticle electronic structure has been achieved for all cells expansion using recently developed HSE03+G0W0 scheme. These results used to compute configurational averages fundamental band gaps densities states. A strongly nonlinear behavior is observed it quantified means...