Related papers: Close inspection of plasmon excitations in cuprate…
We examine the nature of the collective excitations in a strongly anisotropic system of bosons interacting via Coulomb interaction. Such a system has often been used in the past to model the effects of quantum and classical phase…
The doping and energy evolution of the magnetic excitations of the electron-doped cuprate superconductor Pr$_{0.88}$LaCe$_{0.12}$CuO$_{4-\delta}$ in the superconducting state is studied based on the kinetic energy driven superconducting…
The existence and nature of a new mode of electronic collective excitations (quadrupole plasmons) in confined one-dimensional electronic systems have been predicted by an eigen-equation method. The eigen-equation based on the time-dependent…
Renormalization of the Coulomb interaction in layered metals results in a strongly anisotropic plasma mode with low frequencies for small components of wave vector in the in-plane direction. Interaction of electrons with this mode was found…
We analyze collective excitations in models of two-dimensional topological insulators using the random phase approximation. In a two-dimensional extension of the Su-Schrieffer-Heeger model, edge plasmonic excitations with induced…
In this work we investigate a low dimensional semiconductor system, in which the light-matter interaction is enhanced by the cooperative behavior of a large number of dipolar oscillators, at different frequencies, mutually phase locked by…
The collective excitation spectra are studied for a multisubband quasi-one-dimensional electron gas on the surface of liquid helium. Different intersubband plasmon modes are identified by calculating the spectral weight function of the…
We investigate electronic excitations in La2-x(Br,Sr)xCuO4 using resonant inelastic x-ray scattering (RIXS) at the oxygen K edge. RIXS spectra of the hole-doped cuprates show clear momentum dependence below 1 eV. The spectral weight…
Within the t-t'-J model, the doping dependence of charge dynamics in electron-doped cuprates is studied. The conductivity spectrum shows a pseudogap structure with a low-energy peak appearing at $\omega\sim 0$ and an rather sharp…
We report a resonant inelastic x-ray scattering study of the dispersion relations of charge transfer excitations in insulating La$_2$CuO$_4$. These data reveal two peaks, both of which show two-dimensional characteristics. The lowest energy…
Strong electron correlations drive Mott insulator transitions. Yet, there exists no framework to classify Mott insulators by their degree of correlation. Cuprate superconductors, with their tunable doping and rich phase diagrams, offer a…
In this article, we discuss the non-trivial collective charge excitations (plasmons) of the extended square-lattice Hubbard model. Using a fully non-perturbative approach, we employ the hybrid Monte Carlo algorithm to simulate the system at…
The nature of low energy plasmon excitations plays an important role in understanding the low energy electronic properties and coupling mechanism of different superconducting compounds such as CaC$_6$. Recent ab-initio studies predict a…
Momentum resolved inelastic resonant x-ray scattering is used to map the evolution of charge excitations over a large range of energies, momenta and doping levels in the electron doped Mott insulator class Nd$_{2-x}$Ce$_x$CuO$_4$. As the…
I calculate the effect of interactions among superconducting quasiparticles in two-dimensional(2D) a superconductor at T=0. The strength of the effective interaction among the quasiparticles is essentially given by the screened Coulomb…
The resonant inelastic x-ray scattering spectrum in insulating cuprates is examined by using the exact diagonalization technique on small clusters in the two-dimensional Hubbard model with second and third neighbor hopping terms. When the…
Electron energy-loss spectroscopy studies have been performed in order to get a deeper insight into the electronic structure and elementary excitations of the two-leg ladder system Ca$_{11}$Sr$_3$Cu$_{24}$O$_{41}$. We find a strong…
We investigate high-energy spin excitations in hole-doped La$_{2-x}$Ca$_{x}$CuO$_{4-\delta}$ films across a broad Ca doping range $x = 0.05-0.50$ using resonant inelastic x-ray scattering (RIXS). Polarization analysis and incident-photon…
A strong coherent superposition is shown to be induced between the energy states of a two-level emitter immersed in a surface plasmon polariton evanescently confined to a small metallic ring. It turns out that there is nearly equal chance…
Charge order has now been observed in several cuprate high-temperature superconductors. We report a resonant inelastic x-ray scattering experiment on the electron-doped cuprate Nd$_{2-x}$Ce$_{x}$CuO$_4$ that demonstrates the existence of…