Purely Electrical Controllable Spin–Orbit Torque‐Based Reconfigurable Physically Unclonable Functions

• Published in: Advanced electronic materials 2023-05, Vol.9 (5), p.n/a
• Main Authors: Zhao, Xiaonan, Wang, Xiujuan, Dong, Yanan, Wang, Wei, Bai, Lihui, Chen, Yanxue, Kang, Shishou, Yan, Shishen, Tian, Yufeng
• Format: Article
• Language: English
• Subjects: Anisotropy; Bit error rate; Cobalt base alloys; Cobalt compounds; Controllability; Current pulses; electrical manipulation; Heterojunctions; Intermetallic compounds; Magnetic fields; Manufacturing; Nanofabrication; Platinum compounds; Random access memory; Reconfigurable hardware; reconfigurable physically unclonable functions; Reconfiguration; Security; Spintronics; spin–orbit torque; Switching (polarity); Torque
• ISSN: 2199-160X; 2199-160X
• DOI: 10.1002/aelm.202201268

In the field of information hardware security, random variations obtained during device manufacturing process play a key role in generating unique and unclonable security keys. Existing physical unclonable functions (PUFs) utilizing these static randomnesses usually exhibit static challenge‐response pairs, which cannot be refreshed and limit their application prospects. Here, it is demonstrated that purely electrical controllable spin–orbit torque (SOT)‐based reconfigurable PUFs (rPUFs) can be realized in Pt/IrMn/Co/Ru/CoPt heterojunctions. By applying current pulses along two orthogonal directions, both the exchange bias between IrMn and Co and the SOT switching polarity (clockwise or counterclockwise) of perpendicularly magnetized CoPt can be reversibly controlled, which enables the realization of four rPUF states within a single device. By taking advantages of the sample growth and micro‐nanofabrication induced variations in the critical switching current density of SOT‐driven magnetization switching, the rPUF device with relatively good uniqueness and low bit error rate is achieved. Our work provides an approach to information hardware security and broadens the application of spintronics. Purely electrical controllable reconfigurable physically unclonable functions (rPUFs) are demonstrated based on field‐free spin–orbit torque induced magnetization switching in Pt/IrMn/Co/Ru/CoPt heterojunctions. By applying current pulses along two orthogonal directions, every heterojunction can be manipulated into four different magnetic configurations. Further utilizing the variations in the critical switching current density, a highly stable rPUF device containing 60 heterojunctions is realized.