Related papers: Unfolding optical transition weights of impurity m…
Exploring the transport properties of different materials brings new avenue for basic understanding of emergent phenomena and practical applications in many different fields. Here, we report a program named as TRACK (TRAnsport properties…
We compute how elastic deformations of optical fibers affect light propagation therein. Specifically, we consider differences in wave-guiding properties of straight fibers subject to different external temperatures, pressures, and…
In this paper, a general methodology to study rigorously discontinuities in open waveguides is presented. It relies on a full vector description given by Maxwell's equations in the framework of the finite element method. The discontinuities…
Understanding DC electrical conductivity is crucial for the study of materials. Macroscopic DC conductivity can be calculated from first principles using the Kubo-Greenwood equation. The procedure involves finding the thermodynamic limit of…
The Hubbard model, which augments independent-electron band theory with a single parameter to describe electron-electron correlations, is widely regarded to be the `standard model' of condensed matter physics. The model has been remarkably…
We have performed a theoretical study of electronic transport in single and bilayer graphene based on the standard linear-response (Kubo) formalism and continuum-model descriptions of the graphene band structure. We are focusing especially…
The optical conductivity of freely suspended graphene was examined under non-equilibrium conditions using femtosecond pump-probe spectroscopy. We observed a conductivity transient that varied strongly with the electronic temperature,…
A first comprehensive treatment on complex eigenmodes is presented for general lossy traveling-wave electromagnetic structures where the per unit length propagation phase shift ($\beta$) dependent complex eigenfrequencies $\Omega(\beta)$…
Transport properties of irradiated graphene (electrical conductivity and mobility) are numerically investigated using the real-space Kubo formalism. A micrometer-sized system consisting of millions of atoms with nanopores of various sizes…
We explore the charge transport mechanism in organic semiconductors based on a model that accounts for the thermal intermolecular disorder at work in pure crystalline compounds, as well as extrinsic sources of disorder that are present in…
The band-unfolding method is widely used to calculate the effective band structures of a disordered system from its supercell model. The unfolded band structures show the crystallographic symmetry of the underlying structure, where the…
We numerically calculate the optical conductivity of twisted graphene bilayers within the continuum model. To obtain the imaginary part, we employ the regularized Kramers-Kronig relation allowing us to discuss arbitrary twist angles,…
We calculate the optical conductivity in a clean system of quasiparticles coupled to charge-ordering collective modes. The absorption induced by these modes may produce an anomalous frequency and temperature dependence of low-energy optical…
Loss is inevitable for the optical system due to absorption of materials, scattering caused by the defects and surface roughness. In quantum optical circuits, the loss can not only reduce the intensity of signal, but also affect the…
We validate that off-resonant electron transport across {\it ultra-short} oligomer molecular junctions is characterised by a conductance which decays exponentially with length, and we discuss a method to determine the damping factor via the…
Due to the need for higher reliability and performance from RF circuits, multi-port reflectometers are increasingly used as low-overhead impedance monitors. In this work, using periodic structures as multi-ports is proposed. Periodic…
First-principles calculation of nonlinear magneto-optical effects has become an indispensable tool to reveal the geometric and topological nature of electronic states and to understand light-matter interactions. While intriguingly rich…
Flat electronic bands enhance electron-electron interactions and give rise to correlated states such as unconventional superconductivity or fractional topological phases. However, most current efforts towards flat-band materials discovery…
We present a fully first-principles method for superconducting thin films. The layer dependent phonon spectrum is calculated to determine the layer dependence of the electron-phonon coupling for such systems, which is coupled to the…
The calculations of electronic transport coefficients and optical properties require a very dense interpolation of the electronic band structure in reciprocal space that is computationally expensive and may have issues with band crossing…