Related papers: Dielectric properties of multiband electron system…
Recent magnetotransport experiments on high mobility two-dimensional electron systems have revealed many-body electron states unique to high Landau levels. Among these are re-entrant integer quantum Hall states which undergo sharp…
Nesting in a semimetal can lead to an excitonic insulator state with spontaneous coherence between conduction and valence bands and a gap for charged excitations. In this paper we present a theory of the ferromagnetic state that occurs when…
The collective modes of striped phases in a quantum Hall system are computed using the time-dependent Hartree-Fock approximation. Uniform stripe phases are shown to be unstable to the formation of modulations along the stripes, so that…
We investigate intra-Landau-level collective excitations in a bilayer disordered two-dimensional electron system exposed to a perpendicular magnetic field. The energy spectrum is calculated within the random phase approximation by taking…
Collective electronic excitations, including plasmons, excitons, and intra- and interband transitions, play a central role in determining the dynamic screening, optical response, and energy transport properties of materials. Recent advances…
We introduce different types of quenches to probe the non-equilibrium dynamics and multiple collective modes of bilayer fractional quantum Hall states. We show that applying an electric field in one layer induces oscillations of a spin-1…
Density-density response functions are evaluated for nondegenerate multisubband electron systems in the random-phase approximation for arbitrary wave number and subband index. We consider both quasi-two-dimensional and quasi-one-…
Charge dynamics in a dimer Mott insulating system, where a non-polar dimer-Mott (DM) phase and a polar charge-ordered (CO) phase compete with each other, are studied. In particular, collective charge excitations are analyzed in the three…
Excitons in the weakly interacting regime can be well-described by many-body perturbation theories such as the Bethe-Salpeter equation formalism. However, for materials such as transition metal dichalcogenides moir\'e heterostructures under…
The quantum dynamics of a dense and dipole-dipole coupled ensemble of two-level emitters interacting via their environmental thermostat is investigated. The static dipole-dipole interaction strengths are being considered strong enough but…
The quantum states of an electron-hole pair in one-dimensional semiconductors under a static electric field are theoretically analyzed using a two-band model with on-site Coulomb interaction. In the absence of static field, the electron and…
The specific character of longitudinal collective electromagnetic oscillations in a layered conductor with the quasi-two-dimensional electron energy spectrum has been analyzed.
There are two types of two-photon transitions in molecular aggregates, that is, non-local excitations of two monomers and local double excitations to some higher excited intra-monomer electronic state. As a consequence of the inter-monomer…
We re-examine the effect of long-range Coulomb interactions on the collective amplitude and phase modes in the incommensurate charge-density-wave ground state of quasi-one-dimensional conductors. Using an effective action approach we show…
We present a systematic study of the response properties of two-band (multi-gap) superconductors with spin-singlet (s-wave) pairing correlations, which are assumed to be caused by both intraband (\lambda_{ii}, i=1,2) and interband…
We investigate the plasmon dispersion relation and damping rate of collective excitations in a double-layer system consisting of bilayer graphene and GaAs quantum well, separated by a distance, at zero temperature with no interlayer…
The "metallic" regime of holes in GaAs/AlGaAs heterostructures corresponds to densities where two splitted heavy hole bands exist at a zero magnetic field. Using Landau fan diagrams and weak field magnetoresistance curves we extract the…
A model to describe electronic correlations in energy bands is considered. The model is a generalization of the conventional Hubbard model that allows for the fact that the wavefunction for two electrons occupying the same Wannier orbital…
The magnetoelectronic properties of quasi-one-dimensional zigzag graphene nanoribbons are investigated by using the Peierls tight-binding model. Quasi-Landau levels (QLLs), dispersionless Landau subbands within a certain region of k-space,…
The mixing of states with {\it opposite chirality} in quantum Hall system is shown to have delocalization effect. It is possible that extended states may form bands because of this mixing, as is shown through a numerical calculation on a…