We present a promising route to realize spontaneous magnetic order on the surface of a 3D topological insulator by applying a superlattice potential. The superlattice potential creates tunable van Hove singularities, which, when combined with strong spin-orbit coupling and Coulomb repulsion give rise to a topological meron lattice spin texture. The periodicity of this designer meron lattice can be tuned by varying the periodicity of the superlattice potential. We characterize the magnetic order using Ginzburg-Landau theory and show that the magnetic transition temperature reaches experimentally accessible values. Our work introduces a new direction to realize exotic quantum order by engineering interacting Dirac electrons in a superlattice potential, with promising applications to spintronics.
@article{arxiv.2203.04986,
title = {Designer Meron Lattice on the Surface of a Topological Insulator},
author = {Daniele Guerci and Jie Wang and J. H. Pixley and Jennifer Cano},
journal= {arXiv preprint arXiv:2203.04986},
year = {2022}
}