相关论文: Structural relaxations in electronically excited p…

We investigate the relaxation energies and excited state geometries of the light emitting polymer, poly(para-phenylene). We solve the Pariser-Parr-Pople-Peierls model using the density matrix renormalization group method. We find that the…

The exciton relaxation dynamics of photoexcited electronic states in poly($p$-phenylenevinylene) (PPV) are theoretically investigated within a coarse-grained model, in which both the exciton and nuclear degrees of freedom are treated…

Excitons in the weakly interacting regime can be well-described by many-body perturbation theories such as the Bethe-Salpeter equation formalism. However, for materials such as transition metal dichalcogenides moir\'e heterostructures under…

The two-state molecular orbital model of the one-dimensional phenyl-based semiconductors is applied to poly(p-phenylene vinylene). The energies of the low-lying excited states are calculated using the density matrix renormalization group…

We report on a theoretical study of the fine structure of excited excitonic levels in semiconductor quantum disks. A particular attention is paid to the effect of electron-hole long-range exchange interaction. We demonstrate that, even in…

We consider the reduced dynamics of a molecular chain weakly coupled to a phonon bath. With a small and constant inhomogeneity in the coupling, the excitation relaxation rates are obtained in closed form. They are dominated by transitions…

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…

Component of photoexcited states with large spatial extent is investigated for optical absorption spectra of the electroluminescent conjugated polymers by using the intermediate exciton theory. We calculate the ratio of oscillator strengths…

We present a theoretical analysis of the phonon-assisted relaxation in a system composed of two self-assembled vertically stacked quantum dots. We construct realistic model, which takes into account the geometry and strain distribution in…

Attachment of chemical substituents (such as polar moieties) constitutes an efficient and convenient way to modify physical and chemical properties of conjugated polymers and oligomers. Associated modifications in the molecular electronic…

Electron-phonon and exciton-phonon interactions in nanoclusters are formulated and computed under the framework of GW-BSE (Bethe-Salpeter equation) approach. The phonon effect is modeled with the two-particle representation for the first…

A computational scheme for the investigation of complex materials with strongly interacting electrons is formulated which is able to treat atomic displacements, and hence structural relaxation, caused by electronic correlations. It combines…

We theoretically study energy relaxation via LO-phonon emission in an excited one-dimensional electron gas confined in a GaAs quantum wire structure. We find that the inclusion of phonon renormalization effects in the theory extends the…

Electron-hole (e-h) capture in luminescent conjugated polymers (LCPs) is modeled by the dissipative dynamics of a multilevel electronic system coupled to a phonon bath. Electroinjected e-h pairs are simulated by a mixed quantum state, which…

Density matrix renormalisation group calculations of a suitably parametrised model of long polyenes (polyacetylene oligomers), which incorporates both long range Coulomb interactions and adiabatic lattice relaxation, are presented. The…

The relaxation process of electron spin in systems of electrons interacting with piezoelectric deformation phonons that are mediated through spin-orbit interactions was interpreted from a microscopic point of view using the formula for the…

Lattice relaxation profoundly reshapes electronic structures in twisted materials. Prevailing treatments, however, typically rely on large-scale density functional theory (DFT), which is computationally costly and mechanistically opaque.…

The localization length of a low energy tightly bound electron-hole pair (excitons) is calculated by exact diagonalization for small interacting disordered systems. The exciton localization length (which corresponds to the thermal…

Organic semiconducting polymers are currently of broad interest as potential low-cost materials for photovoltaic and light-emitting display applications. I will give an overview of our work in developing a consistent quantum dynamical…

In this work we perform electron energy-loss spectroscopy (EELS) of freestanding graphene with high energy and momentum resolution to disentangle the quasielastic scattering from the excitation gap of Dirac electrons close to the optical…