Nearest-neighbor sp3s* tight-binding parameters based on the hybrid quasi-particle self-consistent GW method verified by modeling of type-II superlattices

Abstract

We report the determination of parameters for the nearest-neighbor sp3s* tight-binding (TB) model for GaP, GaAs, GaSb, InP, InAs, and InSb at 0, 77, and 300 K based on the hybrid quasi-particle self-consistent GW (QSGW) calculation and their application to a type II (InAs)/(GaSb) superlattice. The effects of finite temperature have been incorporated empirically by adjusting the parameter for blending the exchange-correlation terms of the pure QSGW method and local density approximation, in addition to the usage of experimental lattice parameters. As expected, the TB band gap shrinks with temperature and asymptotically with superlattice period when it is large. In addition, a bell curve in the band gap in the case of small superlattice period and slight and remarkable anisotropy in effective masses of electron and hole, both predicted by the hybrid QSGW method, respectively, are reproduced.

A finite electric-field approach to evaluate the vertex correction for the screened Coulomb interaction in the quasiparticle self-consistent GW method

“…In contrast to the other GW methods which requires the Wannierinterpolation technique to make band plots in the whole Brillouin zone, we can make band plots easily without resorting to the technique [7]. The QSGW80 is successfully used for practical applications, for example, to the type-II superlattice of InAs/GaSb [17,18]. Our present results support the method of QSGW80, which takes only the 80 percent of QSGW self-energy.…”

Hybrid Atomic Orbital Basis from First Principles: Bottom-Up Mapping of Self-Energy Correction to Large Covalent Systems

“…Self-energy-corrected TB parameters in the HAWO basis are calculated by substituting E k⃗ , n KS in eq by quasiparticle energies E k⃗ , n QP obtained at the G 0 W 0 level, which is the first-order non-self-consistent GW approximation of MBPT. , Within the GW approximation, the quasi-particle energies are approximated as where V xc KS is the mean-field exchange–correlation potential and Σ is the self-energy operator derived by considering the many-electron effects as a perturbation treated within a self-consistent framework of Dyson’s equation formulated in terms of the one-particle dynamic nonlocal Green’s function constructed from the KS states. Similar efforts have been reported in recent years on incorporating the SEC in TB parameters computed in terms of the maximally localized Wannier functions. − Incorporation of the SEC in TB parameters has also been attempted through matching specific bands of the QP structure. − …”

Atomistic tight binding study of quantum confined Stark effect in GaBi x As1−x /GaAs quantum wells

“…We note that our sp 3 s * tight-binding parameters reproduce the GaBi band structure very accurately around the Γ point, however the high energy conduction bands do not quantitatively match the published band structure, in particular along the Γ to X direction of the Brillouin zone. This is related to the limitation of the sp 3 s * parametrisation as discussed in the previous studies [27,28]. However, for the GaBiAs material which is a direct band-gap material, the fitted sp 3 s * tight-binding parameters provide a very good description of the band structure properties.…”