Topological Kondo Insulator from Spin Loop Currents
Abstract
We demonstrate that interacting electrons in AB-stacked realize a topological Kondo insulator at hole filling per moir\'e unit cell. In the presence of only local correlations, a symmetry of the moir\'e-scale bandstructure enforces a compensated topological semimetal by tying band inversion to band overlap. We show that non-local interactions change the physics qualitatively, since they allow intrinsic, quantum-geometry-induced spin loop currents to feed back on the effective bandstructure, which lift the remaining accidental degeneracies and open a full gap in the spectrum, leading to a fully gapped topological Kondo insulator. We establish this using real-frequency dynamical mean-field theory to capture Kondo physics alongside Hartree-Fock for non-local interactions. The topological Kondo insulator emerges at intermediate displacement fields, where strong correlations manifest through an enhanced spin susceptibility, a suppressed charge susceptibility, and a stronger thermal dependence of the resistivity. Our results are in good agreement with recent experiments on bilayers demonstrating topological to trivial phase transitions controlled by the displacement field.
Cite
@article{arxiv.2604.11739,
title = {Topological Kondo Insulator from Spin Loop Currents},
author = {Andreas Gleis and Kevin Lucht and Po-Jui Chen and Daniele Guerci and Andrew J Millis and J. H. Pixley},
journal= {arXiv preprint arXiv:2604.11739},
year = {2026}
}