Skyrmions are topological spin textures of interest for fundamental science and applications. Previous theoretical studies have focused on systems with broken bulk inversion symmetry, where skyrmions are stabilized by easy-axis anisotropy. We investigate here systems that break surface inversion symmetry, in addition to possible broken bulk inversion. This leads to two distinct Dzyaloshinskii-Moriya (DM) terms with strengths D⊥, arising from Rashba spin-orbit coupling (SOC), and D∥ from Dresselhaus SOC. We show that skyrmions become progressively more stable with increasing D⊥/D∥, extending into the regime of easy-plane anisotropy. We find that the spin texture and topological charge density of skyrmions develops nontrivial spatial structure, with quantized topological charge in a unit cell given by a Chern number. Our results give a design principle for tuning Rashba SOC and magnetic anisotropy to stabilize skyrmions in thin films, surfaces, interfaces and bulk magnetic materials that break mirror symmetry.
@article{arxiv.1509.07508,
title = {Skyrmions in Chiral Magnets with Rashba and Dresselhaus Spin-Orbit Coupling},
author = {James Rowland and Sumilan Banerjee and Mohit Randeria},
journal= {arXiv preprint arXiv:1509.07508},
year = {2016}
}