Related papers: Electron linewidths of wide--gap insulators: excit…
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…
Starting from the many-body Bethe-Salpeter equation we derive an exchange-correlation kernel $f_{xc}$ that reproduces excitonic effects in bulk materials within time-dependent density functional theory. The resulting $f_{xc}$ accounts for…
Linear and nonlinear optical properties of low dimensional nanostructures have attracted a large interest in the scientific community as tools to probe the strong confinement of the electrons and for possible applications in optoelectronic…
The near- and far-field photoluminescence spectra of a gated two-dimensional electron gas have been measured. Spatial fluctuations in the electron density are found to be manifested as spatial fluctuations in the emission amplitude of the…
Floquet engineering of electronic states by light is a central topic in modern experiments. However, the impact of many-body interactions on the single-electron properties remains unclear in this non-equilibrium situation. We propose that…
We present a self-consistent treatment of the electron-hole correlations in optically excited quantum wires within the ladder approximation, and using a contact potential interaction. The limitations of the ladder approximation to the…
We investigate the description of excitonic effects within time-dependent density-functional theory (TDDFT). The exchange-correlation kernel f_xc introduced in TDDFT allows a clear separation of quasiparticle and excitonic effects. Using a…
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…
We study the effect of electron-electron interactions in the optical conductivity of graphene under applied bias and derive a generalization of Elliot's formula, commonly used for semiconductors, for the optical intensity. We show that {\it…
We present first-principles calculations of the linewidths of low-energy quasiparticles in n-doped graphene arising from both the electron-electron and the electron-phonon interactions. The contribution to the electron linewidth arising…
We review the effects of Coulomb correlation on the linear and non-linear optical properties of semiconductor quantum wires, with emphasis on recent results for the bound excitonic states. Our theoretical approach is based on generalized…
It is demonstrated that the bootstrap kernel [\onlinecite{sharma11}] for finite values of ${\bf q}$ crucially depends upon the matrix character of the kernel and gives results of the same good quality as in the ${\bf q} \rightarrow 0$…
Significant excitonic effects were observed in graphene by measuring its optical conductivity in a broad spectral range including the two-dimensional {\pi}-band saddle-point singularities in the electronic structure. The strong…
Applying the novel exact-exchange (EXX) Kohn-Sham method within time-dependent density-functional theory, we obtained the optical absorption spectrum of bulk silicon in good agreement with experiments including excitonic features. Analysis…
In the description of the interaction between electrons beyond the classical Hartree picture, bare exchange often yields a leading contribution. Here we discuss its effect on optical spectra of solids, comparing three different frameworks:…
We derive a two-term asymptotic expansion for the exchange energy of the free electron gas on strictly tessellating polytopes and fundamental domains of lattices in the thermodynamic limit. This expansion comprises a bulk (volume-dependent)…
We study transport properties of weakly interacting spinless electrons in one-dimensional single channel quantum wires. The effects of interaction manifest as three-particle collisions due to the severe constraints imposed by the…
The effective potential of electron--electron interaction and the two-particle \textquotedblleft density--density\textquotedblright\ correlation function have been calculated for a simple semiinfinite metal making allowance for the…
Using the projector-based renormalization method we investigate the formation of the excitonic insulator phase in the two-dimensional (2D) spinless Falicov-Kimball model with dispersive $f$ electrons and address the existence of excitonic…
Linear-response time-dependent density-functional theory (TDDFT) can describe excitonic features in the optical spectra of insulators and semiconductors, using exchange-correlation (xc) kernels behaving as $-1/k^{2}$ to leading order. We…