Journal
PHYSICAL REVIEW B
Volume 95, Issue 22, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.95.224424
Keywords
-
Funding
- Japan Society for the Promotion of Science
- Program for Leading Graduate Schools (ALPS)
- KAKENHI [16H06590]
- Strategic Programs for Innovative Research (SPIRE)
- MEXT
- Computational Materials Science Initiative (CMSI), Japan
- Grants-in-Aid for Scientific Research [16H06590] Funding Source: KAKEN
Ask authors/readers for more resources
Noncollinear and noncoplanar magnetic textures including Skyrmions and vortices act as emergent electromagnetic fields and give rise to novel electronic and transport properties. We here report a unified understanding of noncoplanar magnetic orderings emergent from the spin-charge coupling in itinerant magnets. The mechanism has its roots in effective multiple spin interactions beyond the conventional Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism, which are ubiquitously generated in itinerant electron systems with local magnetic moments. By carefully examining the higher-order perturbations in terms of the spin-charge coupling, we construct a minimal effective spin model composed of the bilinear and biquadratic interactions with particular wave numbers dictated by the Fermi surface. Taking two-dimensional systems as examples, we find that our effective model captures the underlying physics of the instability toward noncoplanar multiple-Q states discovered recently: a single-Q helical state expected from the RKKY theory is replaced by a double-Q vortex crystal with chirality density waves even for an infinitely small spin-charge coupling on generic lattices [R. Ozawa et al., J. Phys. Soc. Jpn. 85, 103703 (2016)], and a triple-QSkyrmion crystal with a high topological number of two appears while increasing the spin-charge coupling on a triangular lattice [R. Ozawa, S. Hayami, and Y. Motome, Phys. Rev. Lett. 118, 147205 (2017)]. We find that by introducing an external magnetic field, our effective model exhibits a plethora of multiple-Q states. Our effective model will serve as a guide for exploring further exotic magnetic orderings in itinerant magnets, not only in two dimensions but also in three dimensions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available