Altermagnetic Band Splitting in 10 nm Epitaxial CrSb Thin Films
Abstract
Abstract Altermagnets are a newly identified family of collinear antiferromagnets with a 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 Néel transition temperature of around 700 K. Molecular beam epitaxy is used to synthesize CrSb (0001) thin films with thicknesses ranging from 10 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 bulk‐type, 3D 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.
Article Details
Authors (21)
Sandra Santhosh
Dept. of Physics Pennsylvania State University University Park PA 16802 USA
Paul Corbae
Dept. of Electrical and Computer Engineering University of California Santa Barbara CA 93106 USA
Wilson J. Yánez‐Parreño
Dept. of Electrical and Computer Engineering University of California Santa Barbara CA 93106 USA
Supriya Ghosh
Christopher J. Jensen
National Institute of Standards and Technology Gaithersburg MD 20899 USA
Alexei V. Fedorov
Advanced Light Source Lawrence Berkeley National Laboratory Berkeley CA 94702 USA
Makoto Hashimoto
Stanford Synchrotron Radiation Lightsource
Donghui Lu
Stanford Synchrotron Radiation Lightsource
Julie A. Borchers
National Institute of Standards and Technology Gaithersburg MD 20899 USA
Alexander J. Grutter
NIST Center for Neutron Research
Timothy R. Charlton
Oakridge National Laboratory Oak Ridge TN 37830 USA
Saurav Islam
Department of Physics, The Pennsylvania State University
Diana Golovanova
Yufei Zhao
State Key Laboratory of Chemical Resource Engineering
Aria Tauraso
Dept. of Physics Pennsylvania State University University Park PA 16802 USA
Anthony Richardella
Department of Physics, The Pennsylvania State University
Binghai Yan
K. Andre Mkhoyan
Christopher J. Palmstrøm
Materials Department, University of California Santa Barbara 3 , Santa Barbara, California 93106,
Yongxi Ou
Dept. of Physics Pennsylvania State University University Park PA 16802 USA
Nitin Samarth
Department of Physics, The Pennsylvania State University