Charge fluctuations in the unconventional metallic state of Li0.9Mo6O17

TL;DR

This paper investigates charge fluctuations in Li0.9Mo6O17, revealing a charge ordering transition driven by Coulomb interactions and its role in the material's unconventional metallic state above superconductivity.

Contribution

It introduces a multi orbital extended Hubbard model to analyze charge order and fluctuations, highlighting a non-conventional charge density wave mechanism.

Findings

Charge ordering transition driven by Coulomb repulsion.

Presence of a softening charge collective mode.

Charge fluctuations contribute to unconventional metallic behavior.

Abstract

Charge fluctuations in the quasi-one-dimensional material Li0.9Mo6O17 are analyzed based on a multi orbital extended Hubbard model. A charge ordering transition induced by Coulomb repulsion is found with a charge ordering pattern different from a conventional charge density wave driven by Fermi surface nesting. The metallic state displays a characteristic charge collective mode which softens signalling the proximity to the transition. We argue that the strong scattering between electrons generated by these charge order fluctuations can lead to the unconventional metallic state observed above the superconducting transition temperature in Li0.9Mo6O17.