In this, the first of three articles on the optical absorption of electrons in half-filled Peierls-distorted chains, we present analytical results for non-interacting tight-binding electrons. We carefully derive explicit expressions for the current operator, the dipole transition matrix elements and the optical absorption for electrons with a cosine dispersion relation of bandwidth W and dimerization parameter δ. New correction (η) terms to the current operator are identified. A broad band-to-band transition is found in the frequency range Wδ < ω < W whose shape is determined by the joint density of states for the upper and lower Peierls subbands and the strong momentum dependence of the transition matrix elements.
|Original language||English (US)|
|Number of pages||12|
|Journal||Philosophical Magazine B: Physics of Condensed Matter; Statistical Mechanics, Electronic, Optical and Magnetic Properties|
|State||Published - Jan 1997|
ASJC Scopus subject areas
- Chemical Engineering(all)
- Physics and Astronomy(all)