Influence of Long-Range Coulomb Interactions on the Metal-Insulator Transition in One-Dimensional Strongly Correlated Electron Systems

TL;DR

This paper investigates how long-range Coulomb interactions affect the metal-insulator transition in one-dimensional strongly correlated electron systems, revealing the formation of a Wigner crystal and changes in charge excitation properties.

Contribution

It demonstrates that unscreened Coulomb forces induce a 1D Wigner crystal and alter the singularity behavior near the transition, highlighting the role of screening in insulating phases.

Findings

Unscreened Coulomb forces lead to a 1D Wigner crystal formation.

Transition singularity shifts from square-root to logarithmic.

Charge excitations in the insulating phase behave as Coulomb solitons.

Abstract

The influence of long-range Coulomb interactions on the properties of one-dimensional (1D) strongly correlated electron systems in vicinity of the metal-insulator phase transition is considered. It is shown that unscreened repulsive Coulomb forces lead to the formation of a 1D Wigner crystal in the metallic phase and to the transformation of the square-root singularity of the compressibility (characterizing the commensurate-incommensurate transition) to a logarithmic singularity. The properties of the insulating (Mott) phase depend on the character of the short-wavelength screening of the Coulomb forces. For a sufficiently short screening length the characteristics of the charge excitations in the insulating phase are totally determined by the Coulomb interaction and these quasipartic les can be described as quasiclassical Coulomb solitons.