Related papers: Optical response of correlated electron systems
A microscopic theory of the electrical conductivity $\sigma(\omega)$ within the t-J model is developed. An exact representation for $\sigma(\omega)$ is obtained using the memory-function technique for the relaxation function in terms of the…
We derive analytical expressions for the spectral moments of the dynamical response functions of the Hubbard model using the high-temperature series expansion. We consider generic dimension $d$ as well as the infinite-$d$ limit, arbitrary…
We study the conductivity of a 3D disordered metal close to the antiferromagnetic instability within the framework of the spin-fermion model using the diagrammatic technique. We calculate the interaction correction $\delta\sigma(\omega,T)$…
We briefly review some basic aspects of transport in clean metals focusing on the role of electron-electron interactions and neglecting the effects of impurities, phonons and interband transitions. Both for small Fermi surfaces of two and…
In this paper we show that the optical conductivity can be calculated to agree with experiment if the details of the electronic states around the Fermi level are taken into account with some care. More precisely, we present a calculation of…
We demonstrate the effect of bandstructure on the superconducting properties of Pb by calculating the strong-coupling features in the optical conductivity, $\sigma(\omega)$, due to the electron-phonon interaction. The importance of momentum…
Umklapp scattering determines the conductivity of clean metals. In typical quasi one-dimensional Fermi liquids with an open Fermi surface, certain pseudo-momenta do not decay by 2-particle collisions even in situations where Umklapp…
We investigated the temperature- and frequency-dependent optical scattering rates in the pseudogap phase of cuprates using model pseudogap and electron-boson spectral density (EBSD) functions. We obtained the scattering rates at various…
Density functional plus dynamical mean field calculations are used to show that in transition metal oxides, rotational and tilting (GdFeO$_3$-type) distortions of the ideal cubic perovskite structure produce a multiplicity of low-energy…
We present a detailed theoretical study of light scattering off superfluid trapped Fermi gas of atoms at zero temperature. We apply Nambu-Gorkov formalism of superconductivity to calculate the response function of superfluid gas due to…
The optical conductivity for the surface excitations for a Topological Insulator as a function of the chemical potential and disorder is considered. Due to the time reversal symmetry the chiral metallic surface states are protected against…
Optical conductivity of the weakly doped two-dimensional repulsive Hubbard model on the square lattice with nearest and next nearest hoppings is calculated within the generalized dynamical-mean field (DMFT+\Sigma_p) approach which includes…
The optical conductivity $\sigma(\omega)$ and the d.c. resistivity $\rho(T)$ within the extended t-J model on a square lattice, as relevant to high-$T_c$ cuprates, are reinvestigated using the exact-diagonalization method for small systems,…
We theoretically study the optical conductivity of the tightbinding model which has two types of the hopping integrals arranged in the Fibonacci sequence. Due to the lack of the translational symmetry, many peak structures appear in the…
We study the optical conductivity sigma(Omega) of an electron system near a quantum-critical point with finite-wavelength ordering. sigma(Omega) vanishes in clean Galilean-invariant systems, unless electrons are coupled to dynamical…
Observed optical reflectivity in the infrared spectral region is compared with theoretical predictions in a strongly coupled electron-phonon system. Starting from a Froehlich Hamiltonian, the spectral functions and their temperature…
An effective Hamiltonian which could model the interaction between a tunneling proton and the conduction electrons of a metal is investigated. A remarkably simple correlation between the motion of the $TLS$-atom and an angular-momentum…
Within the model of elastic impurity scattering, we study how changes in the energy dependence of the electronic density of states (EDOS) $N(\epsilon)$ around the Fermi energy $\epsilon_F$ are reflected in the frequency-dependent optical…
The optical conductivity, $\sigma(\omega)$, of the two dimensional one-band Hubbard model is calculated at finite temperature using exact diagonalization techniques on finite clusters. The in-plane d.c. resistivity, $\rho_{ab}$, is also…
The optical conductivity is the basic defining property of materials characterizing the current response toward time-dependent electric fields. In this work, following the approach of Kubo's response theory, we study the general properties…