Spin-Orbit-Torque-Based Spin-Dice: A True Random-Number Generator

New three-terminal spin dice, a true random number generator, are proposed. The design utilizes spin-orbit torque to hold a bi-stable perpendicular magnetic anisotropy nanomagnet in meta-stability and uses thermal noise as an entropy source to bias the magnet off its metastable state. Once the magnetization is tilted, the built-in anisotropy field of the magnet relaxes the magnetization to the stable state, producing a random bit whose value is determined solely by the thermal noise. Our proposed spin-dice are able to simultaneously achieve high throughput, low-energy, and ease of design even in the presence of process variations. Based on our simulations, our three-terminal spin-dice have the potential to outperform recently proposed spin-dice based on two-terminal magnetic tunnel junctions.