Reconfigurable Physical Unclonable Function Based on Spin-Orbit Torque Induced Chiral Domain Wall Motion

A reliable design of physical unclonable function (PUF) based on spin-orbit torque (SOT) induced domain wall (DW) motion has been proposed and experimentally demonstrated. Magnetic DWs are nucleated and propagate in Ta/CoFeB/MgO heterostructures in which their device-to-device variation enables the PUF, while cycle-to-cycle variation in DW motion enables the reconfigurable design. Furthermore, field-free SOT switching has been observed in the chiral domain wall likely caused by the large Dzyaloshinskii-Moriya interaction (DMI) effect. The proposed DW motion based anti-counterfeiting device shows good promises as a CMOS-compatible PUF for hardware security.