Electron Correlations in Molecular Systems

TL;DR

This paper reviews electron correlations in molecular systems, focusing on ET salts, their phase transitions, and physical properties, highlighting the role of the Hubbard model in describing optical conductivity and electron interactions.

Contribution

It provides a comprehensive review of correlated electrons in ET salts, emphasizing phase transitions and the application of the Hubbard model to optical properties.

Findings

ET salts exhibit Mott transition at high temperatures

Transition from antiferromagnetic to superconducting phase under pressure

Optical conductivity shows a low frequency peak indicating Abrikosov-Suhl resonance

Abstract

A short review of correlated electrons in molecular systems has been performed. Main attention has been focussed on ET salts, which are the d=2 systems. They show the Mott transition in high temperatures and the transition from the antiferromagnetic to the superconducting phase in low temperatures, under a (chemical) pressure. Physical properties (the electrical resistivity, the specific heat, the magnetic susceptibility, the photoemission spectra, the optical conductivity) of ET salts have been compared with those ones in other strongly correlated systems. The optical conductivity is described in the framework of the Hubbard model, with a low frequency peak as an evidence for the Abrikosov-Suhl resonance.