Energy-Efficient Single Layer Spin Hall Nano-Oscillators Driven by Berry Curvature.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40343471.
- Also identified by DOI 10.1021/acsnano.5c02048 and PMC identifier 12096435.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Spin Hall nano-oscillators (SHNOs) are emerging spintronic oscillators with significant potential for technological applications, including microwave signal generation, and unconventional computing. Despite their promising applications, SHNOs face various challenges, such as high energy consumption and difficulties in growing high-quality thin film heterostructures with clean interfaces. Here, single-layer topological magnetic Weyl semimetals open a possible solution as they possess both intrinsic ferromagnetism and a large spin-orbit coupling due to their topological properties. However, producing such high-quality thin films of magnetic Weyl semimetals that retain their topological properties and Berry curvature remains a challenge. We address these issues with high-quality single-layer epitaxial ferromagnetic Co<sub>2</sub>MnGa Weyl semimetal thin film-based SHNOs. We observe a giant spin Hall conductivity, σ<sub>SHC</sub> = (6.08 ± 0.02) × 10<sup>5</sup> (ℏ/2<i>e</i>) Ω<sup>-1</sup> m<sup>-1</sup>, which is an order of magnitude higher than previous reports. Theoretical calculations corroborate the experimental results with a large intrinsic spin Hall conductivity due to presence of a strong Berry curvature. Further, self spin-orbit torque driven magnetization auto-oscillations are demonstrated for the first time, at an ultralow threshold current density of <i>J</i><sub>th</sub> = 6.2 × 10<sup>11</sup> A m<sup>-2</sup>. These findings indicate that magnetic Weyl semimetals have tremendous application potential for developing energy-efficient spintronic devices.