Many-body Chern insulator in the Kondo lattice model on a triangular lattice

TL;DR

This paper demonstrates the emergence of a many-body Chern insulator with a noncoplanar magnetic order in the Kondo lattice model on a triangular lattice, revealing a new route to correlated topological phases.

Contribution

It shows that a triple-Q magnetic order can be the ground state at quarter filling, leading to a quantized many-body Chern number in the Kondo lattice model.

Findings

Triple-Q magnetic order is the ground state at quarter filling.

The many-body Chern number is quantized to one in this phase.

The study uses variational Monte Carlo to reveal these properties.

Abstract

The realization of topological insulators induced by correlation effects is one of the main issues of modern condensed matter physics. An intriguing example of the correlated topological insulators is a magnetic Chern insulator induced by a noncoplanar multiple-Q magnetic order. Although the realization of the magnetic Chern insulator has been studied in the classical limit of the Kondo lattice model, research on the magnetic Chern insulator in the original Kondo lattice model is limited. Here, we investigate the possibility of the many-body Chern insulator with the noncoplanar triple-Q magnetic order in the Kondo lattice model on a triangular lattice. Using the many-variable variational Monte Carlo method, we reveal that the triple-Q magnetic order becomes a ground state at quarter filling in an intermediate Kondo coupling region. We also show that the many-body Chern number is quantized to one in the triple-Q magnetic ordered phase utilizing the polarization operators. Our results provide a pathway for the realization of the many-body Chern insulator in correlated electron systems.