Large electric field induced modulation of spin–orbit torques in Pt/Co heterostructure with CMOS compatible gate oxide

Current-induced spin–orbit torques (SOTs) in heavy metal/ferromagnet heterostructures provide an efficient route for electrical manipulation of magnetization; however, their magnitude is typically fixed during device fabrication. Dynamic and non-volatile control of SOTs using technologically compatible materials, therefore, remains an important challenge. Here, a large voltage-controlled modulation of SOTs in Pt/Co/HfOx heterostructures is demonstrated, enabled by electric-field-driven oxygen ion migration from a CMOS-compatible high-κ HfOx gate oxide. Gate voltage application at room temperature induces reversible oxidation and reduction of the Co layer, accompanied by modification of interfacial chemistry, resulting in pronounced non-volatile modulation of the SOTs. Harmonic Hall measurements reveal modulation of up to fivefold and twofold in the damping-like and field-like SOT effective fields, respectively. The efficient ionic motion is attributed to the high density of oxygen vacancies in e-beam-deposited HfOx, which enables rapid oxygen ion migration under modest gate voltages. These results establish HfOx as an effective and CMOS-compatible platform for electric-field control of spin–orbit torques, providing a practical route toward voltage-programmable spintronic devices.