Chern Kondo Insulator in an Optical Lattice

TL;DR

This paper proposes a method to realize Chern Kondo insulators in optical lattices using laser-assisted orbital hybridization and synthetic gauge fields, predicting a topologically nontrivial phase driven by strong interactions.

Contribution

It introduces a scheme to create and observe Chern Kondo insulators in cold atom systems, combining orbital hybridization, synthetic gauge fields, and strong Hubbard interactions.

Findings

Prediction of a critical Raman coupling for Kondo screening

Identification of a fully gapped topological phase with integer Chern numbers

Proposal for experimental detection via band topology and double occupancy

Abstract

We propose to realize and observe Chern Kondo insulators in an optical superlattice with laser-assisted $s$ and $p$ orbital hybridization and synthetic gauge field, which can be engineered based on the recent cold atom experiments. Considering a double-well square optical lattice, the localized $s$ orbitals are decoupled from itinerant $p$ bands and are driven into a Mott insulator due to strong Hubbard interaction. Raman laser beams are then applied to induce tunnelings between $s$ and $p$ orbitals, and generate a staggered flux simultaneously. Due to the strong Hubbard interaction of $s$ orbital states, we predict the existence of a critical Raman laser-assisted coupling, beyond which the Kondo screening is achieved and then a fully gapped Chern Kondo phase emerges, with the topology characterized by integer Chern numbers. Being a strongly correlated topological state, the Chern Kondo phase is different from the single-particle quantum anomalous Hall state, and can be identified by measuring the band topology and double occupancy of $s$ orbitals. The experimental realization and detection of the predicted Chern Kondo insulator are also proposed.