Abstract
Magnetic skyrmions in two-dimensional (2D) chiral magnets are often stabilized by a combination of a Dzyaloshinskii-Moriya interaction and an external magnetic field. Here, we show that skyrmions can also be stabilized in twisted moiré superlattices with a Dzyaloshinskii-Moriya interaction in the absence of an external magnetic field. Our setup consists of a 2D ferromagnetic layer twisted on top of an antiferromagnetic substrate. The coupling between the ferromagnetic layer and the substrate generates an effective alternating exchange field. We find a large region of the skyrmion crystal phase when the length scales of the moiré periodicity and skyrmions are compatible. Unlike chiral magnets under a magnetic field, skyrmions in moiré superlattices show an enhanced stability for the easy-axis (Ising) anisotropy which can be essential to realize skyrmions since most van der Waals magnets possess easy-axis anisotropy.
Original language | English (US) |
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Article number | L140406 |
Journal | Physical Review B |
Volume | 103 |
Issue number | 14 |
DOIs | |
State | Published - Apr 13 2021 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics