相关论文: Quenching of low-energy optical absorption in bila…
The electronic properties and optical excitations are investigated in the geometry- and field-modulated bilayer graphene systems, respectively, by using the tight-binding model and Kubo formula. The stacking symmetry of bilayer graphene can…
In a joint theoretical and experimental work the optical properties of azobenzene-functionalized self-assembled monolayers (SAMs) are studied at different molecular packing densities. Our results, based on density-functional and many-body…
In this study, we present a first-principles investigation of the electronic and optical properties of gallium nitride (GaN) bilayers, focusing on the influence of interlayer sliding and spacing. In contrast to the earlier studies on…
Energy states below the bandgap of a semiconductor, such as trap states or charge transfer states in organic donor acceptor blends, can contribute to light absorption. Due to their low number density or ultrasmall absorption cross-section,…
The ability to tune the degree of interaction among particles at the nanoscale is highly intriguing. The spectroscopic signature of such interaction is often subtle and requires special probes to observe. To this end, inter-layer excitons…
We study carrier interaction induced many-body effects on the excitonic optical properties of highly photoexcited one-dimensional semiconductor quantum wire systems by solving the dynamically screened Bethe-Salpeter equation using realistic…
Recent studies of La$_3$Ni$_2$O$_7$ have identified a bilayer (2222) structure and an unexpected alternating monolayer-trilayer (1313) structure, both of which feature signatures of superconductivity near 80 K under high pressures. Using…
The low-frequency magneto-optical properties of bilayer Bernal graphene are studied by the tight-binding model with four most important interlayer interactions taken into account. Since the main features of the wave functions are well…
We present a first-principles method for relaxing a material's geometry in an optically excited state. This method, based on the Bethe-Salpeter equation, consists of solving coupled equations for exciton wavefunctions and atomic…
A theoretical interpretation of the photoluminescence excitation spectra of self-organized polar GaN/(Al,Ga)N quantum dots is proposed. A numerical method assuming a realistic shape of the dots and including the built-in electric field…
The optical interaction of light and matter is modeled as an oscillating dipole in a plane wave. We analyze absorption, scattering and extinction for this system by the energy flow, which is depicted by streamlines of the Poynting vector.…
We consider a bilayer system of two-dimensional Bose-Einstein-condensed dipolar dark excitons (upper layer) and bright ones (bottom layer). We demonstrate that the interlayer interaction leads to a mixing between excitations from different…
We study the effects of site dilution disorder on the electronic properties in graphene multilayers, in particular the bilayer and the infinite stack. The simplicity of the model allows for an easy implementation of the coherent potential…
Light trapping in sub-wavelength semiconductor nanowires (NWs) offers a promising approach to simultaneously reducing material consumption and enhancing photovoltaic performance. Nevertheless, the absorption efficiency of a NW, defined by…
We present results for the optical absorption spectra of small-diameter single-wall carbon and boron nitride nanotubes obtained by {\it ab initio} calculations in the framework of time-dependent density functional theory. We compare the…
We theoretically and numerically prove that under an electromagnetic plane wave with linear polarization incident normally to cylindrical passive scatterers, a single energy diagram can integrate absorption, scattering, and extinction cross…
Accurate and efficient calculations of absorption spectra of molecules and materials are essential for the understanding and rational design of broad classes of systems. Solving the Bethe-Salpeter equation (BSE) for electron-hole pairs…
We present a theoretical study of the optical absorption spectrum of small boron-nitride and carbon nanotubes using time-dependent density-functional theory and the random phase approximation. Both for C and BN tubes, the absorption of…
We study theoretically the single-electron triangular zigzag graphene quantum dot in three typical in-plane electric fields. The far-infrared absorption spectra of the dot are calculated by the tight-binding method and then the optical…
In this work we use first principles density-functional theory and Bethe-Salpeter equation together with tight-binding based maximally localized wannier functions (MLWF-TB) to investigate the electronic, optical and topological properties…