Spin dice (physical random number generator using spin torque switching) and its thermal response

Stochastic switching of spin-torque switching in a small-sized magnetic tunnel junction (MTJ) has a unique nature in any kind of solid state devices working at room temperature. The switching probability (P_sw) can be controlled by the amplitude of the injected current with good reproducibility. This means that the results of the spin-torque switching events can be used as an ideal physical random number generator which produces completely unpredictable random numbers. Meanwhile, the unpredictable random numbers are required as the key factor for data encryption. For this reason, we have been developing a physical random number generator, called spin dice [1], using the stochastic spin-torque switching.