Combined topological and Landau order from strong correlations in Chern bands

TL;DR

This paper introduces a new class of quantum states in Chern bands that combine topological order with conventional charge order, demonstrating complex interplay of strong correlations, band topology, and geometric frustration.

Contribution

It reveals the existence of states with both fractional Chern insulator features and charge order, extending understanding beyond single-band models.

Findings

Presence of fractional Hall conductivity

Interchange of ground-state levels with flux insertion

Charge order with trivial degeneracy

Abstract

We present a class of states with both topological and conventional Landau order that arise out of strongly interacting spinless fermions in fractionally filled and topologically non-trivial bands with Chern number $C=\pm 1$. These quantum states show the features of fractional Chern insulators, such as fractional Hall conductivity and interchange of ground-state levels upon insertion of a magnetic flux. In addition, they exhibit charge order and a related additional trivial ground-state degeneracy. Band mixing and geometric frustration of the charge pattern place these lattice states markedly beyond a single-band description.