Electrical Manipulation of Orbital Current Via Oxygen Migration in Ni₈₁ Fe₁₉ /CuO_x /TaN Heterostructure

The orbital Hall effect and the interfacial Rashba effect provide new approaches to generate orbital current and spin-orbit torque (SOT) efficiently without the use of heavy metals. However, achieving efficient dynamic control of orbital current and SOT in light metal oxides has proven challenging. In this study, it is demonstrated that a sizable magnetoresistance effect related to orbital current and SOT can be observed in Ni₈₁ Fe₁₉ /CuO_x /TaN heterostructures with various CuO_x oxidization concentrations. The ionic liquid gating induces the migration of oxygen ions, which modulates the oxygen concentration at the Ni₈₁ Fe₁₉ /CuO_x interface, leading to reversible manipulation of the magnetoresistance effect and SOT. The existence of a thick TaN capping layer allows for sophisticated internal oxygen ion reconstruction in the CuO_x layer, rather than conventional external ion exchange. These results provide a method for the reversible and dynamic manipulation of the orbital current and SOT generation efficiency, thereby advancing the development of spin-orbitronic devices through ionic engineering.