Related papers: Microscopic screening theory for excitons in two-d…
Two-dimensional (2D) materials are increasingly being used as active components in nanoscale devices. Many interesting properties of 2D materials stem from the reduced and highly non-local electronic screening in two dimensions. While…
Atomically thin materials are exceedingly susceptible to their dielectric environment. For transition metal dichalcogenides, sample placement on a substrate or encapsulation in hexagonal boron nitride (hBN) are frequently used. In this…
In the context of photoelectron spectroscopy, the $GW$ approach has developed into the method of choice for computing excitation spectra of weakly correlated bulk systems and their surfaces. To employ the established computational schemes…
The contribution to the binding energy of a two-body system due to the crossed two-boson exchange contribution is calculated, using the Bethe-Salpeter equation. This is done for distinguishable, scalar particles interacting via the exchange…
We propose a new objective numerical figure of merit to aid in the evaluation and comparison of tissue-selective images generated from dual-energy radiography systems. A metric is developed through identification of the requirements of a…
The optical and electronic properties of the {\alpha}-SiTe, {\beta}-SiTe, and RX-SiTe_2 are investigated. A detailed analysis of electronic properties is done using standard density functional theory (DFT) and hybrid functional (HSE06)…
We have constructed a complete quantum theory for an optical process of excitons with nonlocal susceptibility originating from their center-of-mass motion. This theory provides a practical calculation method for arbitrary-structured…
The $GW$-Bethe-Salpeter Equation (BSE) method is promising for calculating the low-lying excited states of molecular systems. So far, it has only been applied to rather small molecules, and in the commonly implemented diagonal…
An alternative methodology to evaluate two-electron-repulsion integrals based on numerical approximation is proposed. Computational chemistry has branched into two major fields with methodologies based on quantum mechanics and classical…
This paper is our progress report on the project "Ising spectroscopy", devoted to systematic study of the mass spectrum of particles in 2D Ising Field Theory in a magnetic field. Here we address the low-temperature regime, and develop…
A GW-BSE approximation scheme is assessed by applying it to a model of asymmetric two-dimensional (2D) interacting electron system. The model is assumed to have a parabolic band characterized by two independent effective mass parameters. A…
We propose an analytical approach for calculating the linear and nonlinear optical (NLO) responses of monolayer transition metal dichalcogenides (TMDs) including excitonic effects. An effective Hamiltonian reproducing the trigonal warping…
Optical responses of atomically thin 2D materials are greatly influenced by electron-hole interactions. It is by far established that exciton signatures can be well-identified in the optical absorption spectrum of quasi-2D materials.…
An ab initio approach is presented for studying the collective excitations in excitonic insulators, charge/spin density waves and superconductors. We derive the Bethe-Salpeter-Equation for the particle-hole excitations in the quasiparticle…
Many-body Green's functions theory within the GW approximation and the Bethe-Salpeter Equation (BSE) is implemented in the open-source VOTCA-XTP software, aiming at the calculation of electronically excited states in complex molecular…
We carry out a detailed theoretical study of the electronic and optical properties of bulk and monolayer bismuth triiodide (BiI$_{3}$), a layered metal halide, using the ab initio GW+BSE scheme with a full spinorial formulation. We discuss…
We show how to calculate the linear and nonlinear optical functions of CdSe nanoplatelets, taking into account the effect of a dielectric confinement on excitonic states. We consider both stationary and non-stationary excitation regime. We…
Although Bayesian density estimation using discrete mixtures has good performance in modest dimensions, there is a lack of statistical and computational scalability to high-dimensional multivariate cases. To combat the curse of…
Spectroscopic and optical properties of nanosystems and point defects are discussed within the framework of Green's function methods. We use an approach based on evaluating the self-energy in the so-called GW approximation and solving the…
By using \textit{ab initio} calculations with the HSE06 hybrid functional and GW approximation combined with numerical solution of the Bethe Salpeter equation (GW-BSE) we predict the existence of diverse number of excitonic states in…