Interface-induced magnetization in altermagnets and antiferromagnets

Abstract

Altermagnets is a class of antiferromagnetic materials which has electron bands with lifted spin degeneracy in momentum space but vanishing net magnetization and no stray magnetic fields. Because of these properties, altermagnets have attracted much attention for potential use in spintronics. We here show that despite the absence of bulk magnetization, the itinerant electrons in altermagnets can generate a magnetization close to edges and vacuum interfaces. We find that surface-induced magnetization can also occur for conventional antiferromagnets with spin-degenerate bands, where the magnetization from the itinerant electrons originates from a subtle yet nonvanishing redistribution of the probability density on the unit-cell level. An intuitive explanation of this effect in a phenomenological model is provided. In the altermagnetic case, the induced magnetization has a different spatial dependence than in the antiferromagnetic case due to the anisotropy of the spin-polarized Fermi surfaces, causing the edge-induced Friedel oscillations of the spin-up and -down electron densities to have different periods. We employ both a low-energy effective continuum model and lattice tight-binding calculations. Our results have implications for the usage of altermagnets and antiferromagnets in nanoscale spintronic applications.

16 pages, 12 figures. Published version

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• When Energy and Information Revolutions Meet 2D Janus
• Phonon-mediated intrinsic topological superconductivity in Fermi arcs
• Cavity-induced coherent magnetization and polaritons in altermagnets
• Visualization of spin-splitter effect in altermagnets via non-equilibrium Green functions on a lattice
• Spin-Polarized Josephson Supercurrent in Nodeless Altermagnets
• $d$-Wave Polarization-Spin Locking in Two-Dimensional Altermagnets
• Viscoelastic tensor and hydrodynamics of altermagnets
• Spin-resolved quasiparticle interference patterns on altermagnets via non-spin-resolved scanning tunneling microscopy
• Altermagnetism from the viewpoint of chemistry