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Abstract Recent studies have demonstrated that the thermal Hall effect (THE) can originate from magnons (magnon Hall effect), phonons (phonon Hall effect), or their combination (magnon–polaron Hall effect). The magnon–polaron Hall effect, first observed in Fe2Mo3O8, is particularly intriguing as its thermal Hall signal can be remarkably large. In this study, we explore the THE in MnPS3, an insulating antiferromagnetic material exhibiting a spin-flop (SF) transition and significant magnetoelastic coupling, making it a strong candidate for studying the THE originating from spin–lattice coupling. We report an exceptionally large thermal Hall angle down to 4 K and show that it cannot be accounted for by standard calculations based on the intrinsic magnon–polaron Berry curvature. Our findings provide an in-depth analysis of the role of the SF transition in the thermal properties of MnPS3and call for further theory development on magnon–phonon coupling and scattering to reveal their influence on transverse heat transport.
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Strain-tuned incompatible magnetic exchange-interaction in La2NiO4
Abstract Magnetic frustration is a route for novel ground states, including spin liquids and spin ices. Such frustration can be introduced through either lattice geometry or incompatible exchange interactions. Here, we find that epitaxial strain is an effective tool for tuning antiferromagnetic exchange interactions in a square-lattice system. By studying the magnon excitations in La2NiO4films using resonant inelastic x-ray scattering, we show that the magnon displays substantial dispersion along the antiferromagnetic zone boundary, at energies that depend on the lattice of the film’s substrate. Using first principles simulations and an effective spin model, we demonstrate that the antiferromagnetic next-nearest neighbour coupling is a consequence of the two-orbital nature of La2NiO4. Altogether, we illustrate that compressive epitaxial strain enhances this coupling and, as a result, increases the level of incompatibility between exchange interactions within a model square-lattice system.
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- Award ID(s):
- 2309000
- PAR ID:
- 10583750
- Publisher / Repository:
- Nature Portfolio
- Date Published:
- Journal Name:
- Communications Physics
- Volume:
- 7
- Issue:
- 1
- ISSN:
- 2399-3650
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1038/s42005-024-01701-x
