Quaternary true random number generator based on single <i>L</i>10-FePt spin–orbit torque device

Abstract

In this work, we experimentally demonstrated the spintronic quaternary true random number generator (QTRNG) utilizing the stochastic switching characteristics of the sub-micrometer-scale L10-FePt spin–orbit torque device. The device exhibits good perpendicular magnetic anisotropy and inherent thermal-fluctuation-induced randomness during magnetization switching. A comparator-based quantization architecture is employed to convert the stochastic analog Hall resistance signals into uniformly distributed quaternary digital outputs, achieving near-ideal randomness with deviations below 2%. Practical implementations explored include a QTRNG-based mosaic masking technique, demonstrating superior visual obfuscation with high Shannon entropy (∼6.88 bits) and convolutional neural networks initialized with QTRNG-derived kernels. This work demonstrates the potential of FePt-based QTRNG systems for reliable multilevel random number generation, establishing a foundation for their integration into advanced spintronic solutions for information security and future deployment in fully spintronic neuromorphic hardware systems.