Inherent stochasticity in phase-change memory devices

A two terminal nanoscale device showing inherent stochastic behavior can be a key enabler for a wide range of applications such as stochastic computing, machine learning and neuromorphic engineering. In this article we investigate the inherent stochasticity associated with two key attributes of phase-change memory devices, namely, threshold switching and memory switching. The physical origin of this stochasticity is traced to the differences in the atomic configurations of the amorphous phase created via the melt-quench process after each RESET operation, which is validated by simulation and experimental results. We also present experimental results for one specific application namely, a true random number generator.