Origin of $A$-type antiferromagnetism and chiral split magnons in altermagnetic $\alpha$-MnTe

Abstract

The origin of the $A$-type antiferromagnetic ordering, characterized by ferromagnetic layers coupling antiferromagnetically, in the prototype semiconductor altermagnet $\alpha$-MnTe has been a topic of ongoing debate. Experimentally, $\alpha$-MnTe exhibits an in-plane ferromagnetic exchange interaction, whereas previous \emph{ab initio} calculations predicted an antiferromagnetic interaction. In this paper, we resolve this discrepancy by considering an expanded set of magnetic configurations, which reveals a ferromagnetic in-plane exchange interaction in agreement with experimental findings. Additionally, we demonstrate that the 10th nearest-neighbor exchange interaction is directionally dependent, inducing a nonrelativistic chiral splitting in the magnon bands, as recently observed experimentally. We further show that applying a compressive strain may significantly enhance both nonrelativistic spin and chiral magnon splittings. The strain can also change the sign of the in-plane exchange interaction. Computing magnetic susceptibility, we show that strain enhances the N{é}el temperature, significantly. Our results highlight the critical importance of convergence in the number of magnetic configurations for spin interactions in antiferromagnetic materials.

4.5 pages, 4 figures, 1 table

References in corpus (24)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Tutorial: A Beginner's Guide to Interpreting Magnetic Susceptibility Data with the Curie-Weiss Law
• Multifunctional Antiferromagnetic Materials with Giant Piezomagnetism and Noncollinear Spin Current
• Broken Kramers' degeneracy in altermagnetic MnTe
• Giant and tunneling magnetoresistance effects from anisotropic and valley-dependent spin-momentum interactions in antiferromagnets
• Altermagnetism: Exploring New Frontiers in Magnetism and Spintronics
• Direct observation of altermagnetic band splitting in CrSb thin films
• Prediction of unconventional magnetism in doped FeSb2
• Antiferromagnetism in RuO${}_2$ as $d$-wave Pomeranchuk instability
• Observation of Giant Band Splitting in Altermagnetic MnTe
• Prediction of low-Z collinear and noncollinear antiferromagnetic compounds having momentum-dependent spin splitting even without spin-orbit coupling
• Large band-splitting in $g$-wave type altermagnet CrSb
• X-ray Magnetic Circular Dichroism in Altermagnetic $\alpha$-MnTe
• Magnetic octupoles as the order parameter for unconventional antiferromagnetism
• Chiral-Split Magnon in Altermagnetic MnTe
• Altermagnetism with Non-collinear Spins
• Two-dimensional altermagnets from high throughput computational screening: symmetry requirements, chiral magnons and spin-orbit effects
• Observation of Spin Splitting in Room-Temperature Metallic Antiferromagnet CrSb
• Non-relativistic spin splitting in compensated magnets that are not altermagnets
• Interplay of altermagnetism and pressure in hexagonal and orthorhombic MnTe
• Stoichiometry-induced ferromagnetism in altermagnetic candidate MnTe
• Antiferromagnetism, spin splitting, and spin-orbit interaction in MnTe
• Benchmarking density functional theory on the prediction of antiferromagnetic transition temperatures
• A deep investigation of NiO and MnO through the first principle calculations and Monte Carlo simulations

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• Systematic Mapping of Altermagnetic Magnons by Resonant Inelastic X-Ray Circular Dichroism
• Tuning the magnetic properties of the spin-split antiferromagnet MnTe through pressure
• Antiferromagnetic resonance in $\alpha$-MnTe
• Quantum geometry and magnon Hall transport in an altermagnet
• Direct ab initio calculation of magnons in altermagnets: method, spin-space symmetry aspects, and application to MnTe