The In₄Se₃Crystal as a Three-Dimensional Imitative Model of Phenomena in One-Dimensional Crystals

Abstract

For three-dimensional charge carriers described by the dispersion ław with quartic terms of the wave vector, the density of states function similar as in the one-dimensional case was determined. This similarity allows the Pekar and Dejgen condenson states in the continuum approximation to exist. The calculated phonon spectrum reveals optical vibrations of a very low frequency, which favours the electron-phonon interaction and creation of the condenson states.

Elementary energy bands concept, band structure, and peculiarities of bonding in β-InSe crystal

“…In addition to the Fivaz law, which is a model dispersion law for layered crystals, other dispersion laws can be present in these semiconductors. These include laws considering anomalous anisotropy and a low‐energy non‐parabolicity, which can cause the electron density of states to behave as a one‐dimensional gas 39. Our study provides important information to analyze these latter dispersion laws in future works.…”

Dispersion Law with a Low-Energy Non-Parabolicity for the Charge Carriers in the In4Se3Crystal and Related Effects

“…It was shown that one can influence their values by applying an external pressure and by doping [4,6]. The dispersion law (1) is not in contradiction with the symmetry principles of its formation for the one-dimensional representation that describes the upper state of the valence band in the Γ point.…”

“…It was used for an explanation of some peculiarities of the kinetic properties in this crystal [7]. The existence of the condenson states owing to the electron-phonon interaction [3,5] is also related to this dispersion law. Experimental investigations of the photoemission spectrum of the In 4 Se 3 crystal [8] have confirmed the unusual dispersion law present for its charge carriers.…”

Non‐standard anisotropy of the energy spectrum of a layered TlGaSe2 crystal

“… a) There exists a low‐energy non‐parabolicity in the dispersion relation $E({\bf k})$ in the direction ${\Gamma} {-} F_{1} $ , that is characteristic for some indium and gallium selenides 12, 33. However, it was not possible to obtain an analytical dispersion law $E({\bf k})$ as a four‐power terms polynomial having different signs near quadratic and biquadratic terms of the wave vector.…”