Unusual plasmon dispersion in the quasi-one-dimensional conductor(TaSe4)2I: Experiment and theory

Abstract

We present a combined experimental and theoretical study of the plasmon dispersion in a quasi-onedimensional conductor, the transition metal tetrachalco-halogenide (TaSe 4 ) 2 I. The dispersion relation, as measured by electron energy-loss spectroscopy in transmission, is quasilinear, which is not expected from the literature. However, we show that the data can be explained within a one-band model, which additionally allows the derivation of the conduction-band dispersion. Thus, contrary to evidence from photoemission measurements, we find no hint for singular properties caused by one dimensionality. ͓S0163-1829͑98͒07419-0͔

Semiconductor-to-metal transition in the bulk of WSe2upon potassium intercalation

“…Such a strong momentum dependent intensity variation has been observed for materials with quite localized excitations such as molecular solids [32,33], but it is rather unusual for materials with strong covalent bonds and a well defined electronic band structure with a sizable band width. would be expected to show a quadratic increase with momentum for a homogeneous electron gas, such a quasi-linear increase has also been observed quite frequently and in some cases it could be related to the band structure of the respective materials [34][35][36].…”

“…Moreover, our data suggest a quasilinear increase of the plasmon energy upon increasing momentum. While the plasmon dispersion would be expected to show a quadratic increase with momentum for a homogeneous electron gas, such a quasi-linear increase has also been observed quite frequently and in some cases it could be related to the band structure of the respective materials [34][35][36].…”

Plasmon excitations in quasi-one-dimensionalK0.3MoO3

“…29 For the latter compound, a quasilinear plasmon-dispersion relation over a wide momentum range for the direction parallel to the 1D axis was found. This behavior could be understood in terms of band-structure effects, treated on the level of the random-phase approximation, in agreement with existing tight-binding ͑TB͒ band-structure calculations.…”

Determination of an effective one-electron spectrum from the plasmon dispersion of nearly optimally dopedBi2Sr2Grigoryan1, Paasch2, Drechsler3 1999Phys. Rev. BSelf Cite210140View full textAdd to dashboardCite

“…Thus, at first glance there seem to be little chance to solve the inverse problem-the extraction of the electronic structure from the measured plasmon dispersion. However, as shown by us recently, 9 for low dimensional systems under special circumstances it is nevertheless possible to get directly information on the band structure near the Fermi level from the plasmon dispersion. In Ref.…”