相关论文: Real-Space Quantification of Exciton Localization …
Most semiconductors, in particular III-V compounds, have a complex valence band structure near the band edge, due to degeneracy at the zone center. One peculiar feature is the warping of the electronic dispersion relations, which are not…
Excitons in atomically-thin semiconductors necessarily lie close to a surface, and therefore their properties are expected to be strongly influenced by the surrounding dielectric environment. However, systematic studies exploring this role…
Wave functions of heavy-hole excitons in GaAs/Al$_{0.3}$Ga$_{0.7}$As square quantum wells (QWs) of various widths are calculated by the direct numerical solution of a three-dimensional Schr\"odinger equation using a finite-difference…
Twisted two-dimensional semiconductors generate a moir\'e landscape that confines excitons (bound electron-hole pairs) into programmable lattices, offering routes to efficient light sources, sensing, and room-temperature information…
We consider a neutral exciton localized on a model p-i-n junction defined in a two-dimensional crystal: MoSe$_2$ and phosphorene, using a variational approach to the effective mass Hamiltonian. The non-homogeneous electric field at the…
We present a detailed analysis of exciton-photon interaction in a microcavity made out of a photonic crystal slab. Here we have analyzed a disk-like quantum dot where an exciton is formed. Excitonic eigen-functions in addition to their…
In low density regime, the fluorescence of Frenkel exitons in crystal slab can be studied without the aid of rotating wave and Mackoffian approximation. The equations for the case of double and triple lattice-layers are now solved exactly…
Orbital magnetic susceptibility involves rich physics such as interband effects despite of its conceptual simplicity. In order to appreciate the rich physics related to the orbital magnetic susceptibility, it is essential to derive a…
Density functional theory (DFT) embedding provides a formally exact framework for interfacing correlated wave-function theory (WFT) methods with lower-level descriptions of electronic structure. Here, we report techniques to improve the…
Standard flavors of density-functional theory (DFT) calculations are known to fail in describing anions, due to large self-interaction errors. The problem may be circumvented by using localized basis sets of reduced size, leaving no…
Exciton-polaritons -- hybrid states of photons and excitons -- offer unique avenues for controlling electronic, optical, and chemical properties of materials. However, their modeling is mostly limited to formalisms that wash out atomistic…
An ab initio Wannier-function-based approach to electronic ground-state calculations for crystalline solids is outlined. In the framework of the linear combination of atomic orbitals method the infinite character of the solid is rigorously…
Excitonic effects in optical spectra and electron-hole pair excitations are described by solutions of the Bethe-Salpeter equation (BSE) that accounts for the Coulomb interaction of excited electron-hole pairs. Although for the computation…
A versatile method for combining density functional theory (DFT) in the local density approximation (LDA) with dynamical mean-field theory (DMFT) is presented. Starting from a general basis-independent formulation, we use Wannier functions…
Excitons are electron-hole pairs appearing below the band gap in insulators and semiconductors. They are vital to photovoltaics, but are hard to obtain with time-dependent density-functional theory (TDDFT), since most standard…
We derive an analytical expression of a Wigner function that approximately describes the time evolution of the one-dimensional motion of a particle in a nonharmonic potential. Our method involves two exact frame transformations, accounting…
Strong light-matter interactions in layered transition metal dichalcogenides (TMDs) open up vivid possibilities for novel exciton-based devices. The optical properties of TMDs are dominated mostly by the tightly bound excitons and more…
In this tutorial we introduce the reader to several theoretical methods of determining the exciton wave functions and the corresponding eigenenergies. The methods covered are either analytical, semi-analytical, or numeric. We make explicit…
We present a real-space formulation and higher-order finite-difference implementation of periodic Orbital-free Density Functional Theory (OF-DFT). Specifically, utilizing a local reformulation of the electrostatic and kernel terms, we…
Optical measurements and first-principles calculations of the band structure and exciton states in direct-gap bulk and few-layer PbI2 indicate that the n = 1 exciton is Frenkel-like in nature in that its energy exhibits a weak dependence on…