Ab initio derivation of electronic low-energy models for C60 and aromatic compounds

TL;DR

This study derives first-principles low-energy electronic models for various C60 and aromatic compounds to analyze how electronic correlations relate to superconductivity, revealing contrasting trends between these classes.

Contribution

The paper provides the first ab initio derivation of extended Hubbard models for twelve compounds, highlighting their strong correlations and differing correlation-superconductivity relationships.

Findings

C60 compounds show positive correlation between correlation strength and Tc.

Aromatic compounds show negative correlation between correlation strength and Tc.

All studied compounds are strongly correlated with similar energy scales.

Abstract

We present a systematic study for understanding the relation between electronic correlation and superconductivity in C60 and aromatic compounds. We derived, from first principles, extended Hubbard models for twelve compounds; fcc K3C60, Rb3C60, Cs3C60 (with three different lattice constants), A15 Cs3C60 (with four different lattice constants), doped solid picene, coronene, and phenanthrene. We show that these compounds are strongly correlated and have a similar energy scale of the bandwidth and interaction parameters. However, they have a different trend in the relation between the strength of electronic correlation and superconducting transition temperature; while the C60 compounds have a positive correlation, the aromatic compounds exhibit negative correlation.