Related papers: Specific many-electron effects in X-ray spectra of…
A short review of the optical and far-infrared measurements on MgB$_{2}$ is given. Multiband and multigap effects are analyzed by comparing optical properties with other experiments and {\em ab initio} calculations. The covered topics are:…
Recent advances in the brilliance of hard-X-ray beamlines and photoelectron momentum microscopy facilitate bulk valence-band mapping and core-level-resolved hard-X-ray photoelectron diffraction (hXPD) for structural analysis in the same…
Superfluidity has recently been reported in double electron-hole bilayer graphene. The multiband nature of the bilayers is important because of the very small band gaps between conduction and valence bands. The long range nature of the…
The detection of X-ray narrow spectral features in the 5-7 keV band is becoming increasingly more common in AGN observations, thanks to the capabilities of current X-ray satellites. Such lines, both in emission and in absorption, are mostly…
The unusual electronic and optical properties of armchair and zigzag graphene nanoribbons (GNRs) subject to in-plane transverse electric and perpendicular magnetic fields have been systematically investigated. Our calculations were carried…
We employ the first-principles GW+Bethe Salpeter equation approach to study the electronic structure and optical absorption spectra of uniaxial strained graphene with many-electron effects included. Applied strain not only induces an…
We study the electron-magnon scattering in bulk Fe, Co, and Ni within the framework of many-body perturbation theory implemented in the full-potential linearized augmented-plane-wave method. To this end, a $\mathbf{k}$-dependent self-energy…
The low energy region of certain transition metal compounds reveals dramatic correlation effects between electrons, which can be studied by photoelectron spectroscopy. Theoretical investigations are often based on multi-orbital impurity…
Multiple reflection of X-rays may be important when an accretion disc and its hot corona have a complicated geometry, or if returning radiation due to gravitational light bending is important, or in emission from a funnel such as proposed…
We present an {\it ab initio} many-body GW calculation of the self-energy, the quasiparticle band plot and the spectral functions in free-standing undoped graphene. With respect to other approaches, we numerically take into account the full…
We present a computationally efficient method to incorporate density-functional theory into the calculation of reflectivity in low-energy electron microscopy. The reflectivity is determined by matching plane waves representing the electron…
We study the orbital effect of a strong magnetic field parallel to the layers on the energy spectrum of the Bernal-stacked graphene bilayer and multilayers, including graphite. We consider the minimal model with the electron tunneling…
We employ Faraday and Kerr effect spectroscopy in the infrared range to investigate the electronic structure of Ga1-xMnxAs near the Fermi energy. The band structure of this archetypical dilute-moment ferromagnetic semiconductor has been a…
We review field theoretical studies dedicated to understanding the effects of electron-electron interaction in graphene, which is characterized by gapless bands, strong electron-electron interactions, and emerging Lorentz invariance deep in…
Theoretical calculations of materials have in recent years shown promise in facilitating the analysis of convoluted experimental data. This is particularly invaluable in complex systems or for materials subject to certain environmental…
By employing the first-principles GW-Bethe-Salpeter Equation (BSE) simulation, we obtain, for the first time, the accurate quasiparticle (QP) band gap, optical absorption spectra and their dependence on the gate field of gated bilayer…
We study the effect of transversal electric-field (E-field) on the electronic properties of multilayer armchair-graphene-nanoribbon (AGNR). The bandgap in multilayer-AGNRs can be reversibly modulated with the application of E-field. At…
Simultaneous observations of Mkn 421 were taken in very high energy gamma -rays (>200 GeV, CAT experiment), X-rays (RXTE) and optical (KVA). Multi -day RXTE observations are also presented, allowing for detailed modelling of the spectral…
Recently Russell et al. [Phys. Rev. Lett. 120, 047401 (2018)] have reported a clear signal of many-particle contributions to cyclotron resonance in high-mobility hBN-encapsulated graphene, observing significant variations of resonance…
The application of imaging techniques based on ensembles of nitrogen-vacancy (NV) sensors in diamond to characterise electrical devices has been proposed, but the compatibility of NV sensing with operational gated devices remains largely…