Related papers: Collective Excitations in High-Temperature Superco…
We have measured dispersions of spin-flip waves and spin-flip single-particle excitations of a spin polarized two-dimensional electron gas in a CdMnTe quantum well using resonant Raman scattering. We find the energy of the spin-flip wave to…
The proximity of antiferromagnetic order in high-temperature superconducting materials is considered a possible clue to the electronic excitations which form superconducting pairs. Here we study the transverse and longitudinal spin…
We present calculations of the single-particle excitation spectrum for a 2D strong-coupling superconductor in a conserving approximation. Spectral weight at low frequency is substantially reduced as the superconducting transition is…
Within the framework of the unrestricted time-dependent density functional theory, we present for the first time an analysis of the relativistic Coulomb excitation of the heavy deformed open shell nucleus $^{238}$U. The approach is based on…
We compare the response of five different models of two interacting electrons in a quantum dot to an external short lived radial excitation that is strong enough to excite the system well beyond the linear response regime. The models…
The possible heavy fermion superconductivity is carefully reexamined in the two-dimensional Kondo lattice model with an antiferromagnetic Heisenberg superexchange between local magnetic moments. In order to establish an effective mean field…
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…
We have analyzed low-temperature behavior of two-dimensional electron gas in polar heterostructures subjected to a high electric field. When the optical phonon emission is the fastest relaxation process, we have found existence of…
Starting from the tight-binding dielectric matrix in the random phase approximation we examine the collective modes and electron-hole excitations in a two-band electronic system. For long wavelengths (${\bf q}\rightarrow0$), for which most…
Simple and physically transparent equations for the linear response of layered superconductors with d-wave symmetry of the order parameter are derived by means of the quasiclassic kinetic theory of superconductivity. Responses to solenoidal…
We discuss a reduction of superconducting transition temperature by the intersite Coulomb repulsion for the d-wave pairing in cuprates. We compare the results found for the spin-fermion model and the extended Hubbard model. We argue that in…
Collective modes in two dimensional topological superconductors are studied by an extended random phase approximation theory while considering the influence of vector field of light. In two situations, the s-wave superconductors without…
Properties of superfluid states of two-dimensional electron systems with critical antiferromagnetic fluctuations are investigated. These correlations are found to result in the emergence of rapidly varying in the momentum space terms in all…
The layered graphene systems exhibit the rich and unique excitation spectra arising from the electron-electron Coulomb interactions. The generalized tight-binding model is developed to cover the planar/buckled/cylindrical structures,…
The role of collective modes in various experiments on the cuprates is investigated. We calculate the neutron scattering, photoemission (ARPES), and Raman scattering intensities below $T_c$ within the fluctuation-exchange (FLEX)…
We have studied properties of quantum charge fluids interacting with random impurities or heavy polarons using a microscopic Hamiltonian with the full many-body Coulomb interaction with the use of variational many-body formalism. At zero…
We examine the internal structure of the heavy fermion condensate, showing that it necessarily involves a d-wave pair of quasiparticles on neighboring lattice sites, condensed in tandem with a composite pair of electrons bound to a local…
We analyze the effect of the non-vanishing range of electron-electron repulsion on the mechanism of unconventional superconductivity. We present asymptotically exact weak-coupling results for dilute electrons in the continuum and for the 2D…
Collective charge-density modes (plasmons) of the clean two-dimensional unpolarized electron gas are stable, for momentum conservation prevents them from decaying into single-particle excitations. Collective spin-density modes (spin…
High temperature cuprate superconductors consist of stacked CuO2 planes, with primarily two dimensional electronic band structures and magnetic excitations, while superconducting coherence is three dimensional. This dichotomy highlights the…