Topological Fermi liquids from Coulomb interactions in the doped Honeycomb lattice

TL;DR

This paper demonstrates the emergence of a topological Fermi liquid with anomalous Hall effect in a doped honeycomb lattice driven by Coulomb interactions, involving Kekulé distortions and spontaneous current patterns.

Contribution

It introduces a new mechanism for topological Fermi liquids arising from Coulomb interactions and Kekulé distortions in the honeycomb lattice, expanding understanding of interaction-driven topological phases.

Findings

Identification of an anomalous Hall metallic state from Coulomb interactions.

Demonstration of Kekulé distortions enabling non-trivial magnetic configurations.

Existence of a topological Fermi liquid with quantized Hall conductivity.

Abstract

We get an anomalous Hall metallic state in the Honeycomb lattice with nearest neighbors only arising as a spontaneously broken symmetry state from a local nearest neighbor Coulomb interaction V . The key ingredient is to enlarge the unit cell to host six atoms that permits Kekul\'e distortions and supports self-consistent currents creating non trivial magnetic configurations with total zero flux. We find within a variational mean field approach a metallic phase with broken time reversal symmetry (T) very close in parameter space to a Pomeranchuk instability. Within the T broken region the predominant configuration is an anomalous Hall phase with non zero Hall conductivity, a realization of a topological Fermi liquid. A T broken phase with zero Hall conductivity is stable in a small region of the parameter space for lower values of V .