Kagome metal-organic frameworks as a platform for strongly correlated electrons

Marius Fuchs,Tilman Schwemmer,Peitao Liu,Giorgio Sangiovanni,Ronny Thomale,Cesare Franchini,Domenico Di Sante

doi:10.1088/2515-7639/ab713b

Abstract

By using first-principles calculations we put forward the Cu-dicyanoanthracene lattice as a platform to investigate strong electronic correlations in the family of Kagome metal-organic frameworks. We show that the low-energy model is composed by molecular orbitals which arrange themselves in a typical Kagome lattice at n = 2/3 filling, where the Fermi level lies at the Dirac point. The Coulomb interaction matrix expressed in this molecular orbitals basis, as obtained by large-scale constrained random-phase approximation calculations, is characterized by local U and non-local parameters exceeding more than ten times the Kagome bandwidth. For such Kagome systems, our findings suggest the possible emergence of peculiar electron–electron collective phenomena, such as an exotic valence bond solid order characterized by modulated bond strengths.

Highlights

Since the discovery of unconventional collective phenomena in high-Tc cuprates, superconducting pairing mechanisms driven by electron–electron interactions have become a predominant center of contemporary research [1]
Focusing on two-dimensional metal-organic frameworks (MOFs), we show that experimentally available organometallic hybrids [16,17,18,19], where metal atoms bond with neighboring molecular groups, promise themselves to be a playground to investigate novel collective electronic phenomena
Upon inclusion of electronic correlations, nesting effects and sublattice interference are known to drive exotic quantum phases of matter upon doping [9], while a long-sought valence bond solid order is expected as the ground state at pristine filling [7]

Summary

17 February 2020

Marius Fuchs1, Peitao Liu2 , Tilman Schwemmer1, Giorgio Sangiovanni1, Ronny Thomale1 , Cesare Franchini2,3 and Domenico Di Sante1 Keywords: electronic correlations, Kagome lattice, organic materials, ab initio calculations, constrained random phase approximation Commons Attribution 4.0 licence.

Introduction

Discussion

Conclusion