English

Chiral Stoner magnetism in Dirac bands

Mesoscale and Nanoscale Physics 2024-09-27 v4

Abstract

Stoner magnetism in bands endowed with Berry curvature is shown to be profoundly influenced by the coupling between spin chirality density s(xs×ys)\vec s\cdot(\partial_x\vec s\times\partial_y\vec s) and Berry's orbital magnetization. The key effect is that carriers moving in the presence of a spin texture see it as a source of a geometric magnetic field coupled to the carrier's orbital motion through a spin-dependent Aharonov-Bohm effect. This emergent spin-orbit interaction effect was recently predicted to enable chiral magnons propagating along system boundaries. Here we show that it also favors chiral spin textures such as skyrmions -- the topologically protected objects with particle-like properties, stabilized in the ground state. The threshold for Stoner instability is found to soften, rendering chiral spin-ordered phases accessible under realistic conditions. We present a detailed analysis of the chiral effect for Bernal bilayer graphene and discuss the unique properties of skyrmion textures in graphene multilayers.

Keywords

Cite

@article{arxiv.2208.02051,
  title  = {Chiral Stoner magnetism in Dirac bands},
  author = {Zhiyu Dong and Leonid Levitov},
  journal= {arXiv preprint arXiv:2208.02051},
  year   = {2024}
}

Comments

14 pgs, 1 fig