Boosting Spin‐Orbit Torque Efficiency and Dzyaloshinskii–Moriya Interaction in Perpendicular Magnetic Heterostructures through Nanoscale WTe x Underlayer Engineering
Aleksei G. Kozlov, Fanyu Meng, Ying Feng, Wenbo Li, Tuo Zhang, Zhimba Zh. Namsaraev, Mariya A. Kuznetsova, Alena V. Prikhodchenko, Michail A. Bazrov, Michail E. Letushev, Sofia K. Silina, Nikolay N. Chernousov, Aleksandr V. Davydenko, Alexey V. Ognev, Alexandr S. Samardak, Yi WangABSTRACT
Spin‐orbit torque (SOT) enables ultrafast magnetization switching, while the Dzyaloshinskii–Moriya interaction (DMI) stabilizes chiral spin textures such as skyrmions – both are critical for next‐generation spintronic and skyrmionic devices. Here we show that a disordered WTe x underlayer, deposited by magnetron sputtering, can engineer the Pt/Co/MgO heterostructure at the nanoscale, leading to a 40% enhancement of the damping‐like (DL) SOT efficiency (ξ DL ≈ 0.1 at t Pt = 4 nm) and a 40% reduction of the critical switching current. At larger Pt thickness, the SOT efficiency of the WTe x ‐templated samples remains comparable to that of the reference. Importantly, the DMI constant increases with Pt thickness in all series, reaching up to 3.36 erg/cm 2 in SiO 2 /WTe x /Pt(8 nm)/Co/MgO – a 12% increase over the reference without WTe x . This DMI enhancement is not a direct effect of WTe x but originates from the modified Pt crystallization and interface roughness induced by the WTe x underlayer, as supported by x‐ray reflectometry. X‐ray photoelectron spectroscopy reveals the WTe x layer is non‐stoichiometric (W 0.62 Te 0.38 ) with multiple bonding configurations, suggesting that even disordered transition metal dichalcogenides can locally modulate spin‐orbit coupling and interfacial exchange. These findings establish a design pathway for energy‐efficient SOT‐driven memory and skyrmion‐hosting heterostructures through nanoscale interfacial engineering.