Altermagnetic band splitting in 10 nm epitaxial CrSb thin films

Abstract

Altermagnets are a newly identified family of collinear antiferromagnets with momentum-dependent spin-split band structure of non-relativistic origin, derived from spin-group symmetry-protected crystal structures. Among candidate altermagnets, CrSb is attractive for potential applications because of a large spin-splitting near the Fermi level and a high Neel transition temperature of around 700 K. We use molecular beam epitaxy to synthesize CrSb (0001) thin films with thicknesses ranging from 10 nm to 100 nm. Structural characterization, using reflection high energy electron diffraction, scanning transmission electron microscopy, and X-ray diffraction, demonstrates the growth of epitaxial films with good crystallinity. Polarized neutron reflectometry shows the absence of any net magnetization, consistent with antiferromagnetic order. In vacuo angle resolved photoemission spectroscopy (ARPES) measurements probe the band structure in a previously unexplored regime of film thickness, down to 10 nm. These ARPES measurements show a three-dimensional momentum-dependent band splitting of up to 0.7 eV with g-wave symmetry, consistent with that seen in prior studies of bulk single crystals. The distinct altermagnetic band structure required for potential spin-transport applications survives down to the 10 nm thin film limit at room temperature.

Revisions: author list, comments about ARPES analysis, TEM analysis, and anomalous Hall effect data

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Cited by in corpus (4)

• Dimension- and Facet-Dependent Altermagnetic Biferroics and Ferromagnetic Biferroics and Triferroics in CrSb
• Altermagnetism, ARPES, symmetry, non-relativistic band splitting
• Effect of symmetry breaking on altermagnetism in CrSb and Formation of fragmented nodal curves
• Altermagnetism of ultrathin CrSb slabs