2026/08/03 by David A. Dahlbom, Daniel Kaplan, Premala Chandra +1
Physics and Astronomy · #cond-mat.str-el #cond-mat.mes-hall
15 pages. Comments appreciated
arxiv created 2026/08/03 · arxiv updated 2026/08/05
In low density systems with strong interactions electrons are expected to crystallize into a Wigner solid. Recently, advances in two-dimensional systems where electrons carry Berry curvature have added a topological dimension to Wigner crystallization. Using a model for pseudospin interactions in a topological Wigner crystal, here we show that the competition between ferromagnetic Heisenberg exchange J and the chiral interaction γ on the triangular lattice stabilizes a zero-field skyrmion crystal whose density is continuously tunable through the ratio γ/J. The chiral interaction originates from finite Berry curvature in an underlying time-reversal broken Wigner crystal. In the continuum limit, the chiral interaction acts as a chemical potential for skyrmions, while higher-order gradient terms beyond the nonlinear sigma model select the skyrmion density. At large chiral coupling, we uncover a 24-site tetra-skyrmion crystal carrying four units of topological charge per magnetic unit cell, which becomes degenerate with four-sublattice tetrahedral order as J → 0. We characterize the magnon structure for these phases and discuss the transition between the tunable skyrmion crystal to these states at large γ/J. Our results establish the phase diagram of ferromagnetic topological Wigner crystals.