Observation of Thickness-Modulated Out-of-Plane Spin–Orbit Torque in Polycrystalline Few-Layer Td-WTe2 Film
Mingkun Zheng, Wancheng Zhang, You Lv, Yong Liu, Rui Xiong, Zhenhua Zhang, Zhihong Lu

TL;DR
This study explores how the thickness of Td-WTe2 affects its spin–orbit torque properties, showing potential for use in spintronic devices.
Contribution
The paper reports thickness-modulated out-of-plane spin–orbit torque in polycrystalline few-layer Td-WTe2 films.
Findings
Angle-resolved spin-torque ferromagnetic resonance showed high spin Hall conductivities in Td-WTe2/Ni80Fe20 heterostructures.
Out-of-plane magnetoresistance increased with decreasing Td-WTe2 thickness due to anisotropic charge carrier scattering.
Spin pumping measurements revealed a thickness-dependent out-of-plane spin diffusion length of approximately 14 nm.
Abstract
The low-symmetry Weyl semimetallic Td-phase WTe2 exhibits both a distinct out-of-plane damping torque (τDL) and exceptional charge–spin interconversion efficiency enabled by strong spin-orbit coupling, positioning it as a prime candidate for spin–orbit torque (SOT) applications in two-dimensional transition metal dichalcogenides. Herein, we report on thickness-dependent unconventional out-of-plane τDL in chemically vapor-deposited (CVD) polycrystalline Td-WTe2 (t)/Ni80Fe20/MgO/Ti (Td-WTN-t) heterostructures. Angle-resolved spin-torque ferromagnetic resonance measurements on the Td-WTN-12 structure showed significant spin Hall conductivities of σSH,y = 4.93 × 103 (ℏ/2e) Ω−1m−1 and σSH,z = 0.81 × 103 (ℏ/2e) Ω−1m−1, highlighting its potential for wafer-scale spin–orbit torque device applications. Additionally, a detailed examination of magnetotransport properties in polycrystalline…
Genes, proteins, chemicals, diseases, species, mutations and cell lines named across the full text — each resolved to its canonical identifier and authoritative record.
Click any figure to enlarge with its caption.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsMagnetic properties of thin films · 2D Materials and Applications · Topological Materials and Phenomena
