Title: Molecular Beam Epitaxy Growth of [CrGe/MnGe/FeGe] Superlattices: Toward Artificial B20 Skyrmion Materials with Tunable Interactions,
Abstract: Skyrmions are localized magnetic spin textures whose stability has been shown
theoretically to depend on material parameters including bulk Dresselhaus spin
orbit coupling (SOC), interfacial Rashba SOC, and magnetic anisotropy. Here, we
establish the growth of a new class of artificial skyrmion materials, namely
B20 superlattices, where these parameters could be systematically tuned.
Specifically, we report the successful growth of B20 superlattices comprised of
single crystal thin films of FeGe, MnGe, and CrGe on Si(111) substrates. Thin
films and superlattices are grown by molecular beam epitaxy and are
characterized through a combination of reflection high energy electron
diffraction, x-ray diffraction, and cross-sectional scanning transmission
electron microscopy (STEM). X-ray energy dispersive spectroscopy (XEDS)
distinguishes layers by elemental mapping and indicates good interface quality
with relatively low levels of intermixing in the [CrGe/MnGe/FeGe] superlattice.
This demonstration of epitaxial, single-crystalline B20 superlattices is a
significant advance toward tunable skyrmion systems for fundamental scientific
studies and applications in magnetic storage and logic.