Flexible orbital torque device with ultralow switching current

Abstract

Orbital torque (OT) offers a highly efficient way for electrical magnetization manipulation. However, its potential in the emerging field of flexible spintronics remains largely unexplored. Here, we demonstrate a flexible and robust OT device based on a mica/SrRuO3(SRO)/CoPt heterostructure. We measure a large torque efficiency of −0.31, which originates from the significant orbital Hall effect in the SRO layer. Leveraging the low thermal conductivity of the mica substrate, a thermally assisted switching mechanism is activated, enabling an ultralow threshold current density of 9.2 × 109 A/m2. This value represents a 90% reduction compared to conventional spin torque devices and a 52% reduction against its rigid counterpart on a SrTiO3 substrate. The superior performance is well maintained after 103 bending cycles, confirming its exceptional flexibility and durability. Our work pioneers the development of flexible OT devices, showcasing a viable path toward next-generation, low-power wearable spintronic applications.