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Spin-orbit coupling (SOC), the interaction between the electron spin and the orbital angular momentum, can unlock rich phenomena at interfaces, in particular interconverting spin and charge currents. Conventional heavy metals have been extensively explored due to their strong SOC of conduction electrons. However, spin-orbit effects in classes of materials such as epitaxial 5 d -electron transition-metal complex oxides, which also host strong SOC, remain largely unreported. In addition to strong SOC, these complex oxides can also provide the additional tuning knob of epitaxy to control the electronic structure and the engineering of spin-to-charge conversion by crystalline symmetry. Here, we demonstrate room-temperature generation of spin-orbit torque on a ferromagnet with extremely high efficiency via the spin-Hall effect in epitaxial metastable perovskite SrIrO 3 . We first predict a large intrinsic spin-Hall conductivity in orthorhombic bulk SrIrO 3 arising from the Berry curvature in the electronic band structure. By manipulating the intricate interplay between SOC and crystalline symmetry, we control the spin-Hall torque ratio by engineering the tilt of the corner-sharing oxygen octahedra in perovskite SrIrO 3 through epitaxial strain. This allows the presence of an anisotropic spin-Hall effect due to a characteristic structural anisotropy in SrIrO 3 with orthorhombic symmetry. Our experimental findings demonstrate the heteroepitaxial symmetry design approach to engineer spin-orbit effects. We therefore anticipate that these epitaxial 5 d transition-metal oxide thin films can be an ideal building block for low-power spintronics.
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This content will become publicly available on August 1, 2025
Toward 1D Transport in 3D Materials: SOC‐Induced Charge‐Transport Anisotropy in Sm 3 ZrBi 5
Abstract 1D charge transport offers great insight into strongly correlated physics, such as Luttinger liquids, electronic instabilities, and superconductivity. Although 1D charge transport is observed in nanomaterials and quantum wires, examples in bulk crystalline solids remain elusive. In this work, it is demonstrated that spin‐orbit coupling (SOC) can act as a mechanism to induce quasi‐1D charge transport in the Ln3MPn5(Ln = lanthanide; M = transition metal; Pn = Pnictide) family. From three example compounds, La3ZrSb5, La3ZrBi5, and Sm3ZrBi5, density functional theory calculations with SOC included show a quasi‐1D Fermi surface in the bismuthide compounds, but an anisotropic 3D Fermi surface in the antimonide structure. By performing anisotropic charge transport measurements on La3ZrSb5, La3ZrBi5, and Sm3ZrBi5, it is demonstrated that SOC starkly affects their anisotropic resistivity ratios (ARR) at low temperatures, with an ARR of ≈4 in the antimonide compared to ≈9.5 and ≈22 (≈32 after magnetic ordering) in La3ZrBi5and Sm3ZrBi5, respectively. This report demonstrates the utility of spin‐orbit coupling to induce quasi‐low‐dimensional Fermi surfaces in anisotropic crystal structures, and provides a template for examining other systems.
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- PAR ID:
- 10584463
- Publisher / Repository:
- Advanced Materials
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 36
- Issue:
- 31
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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