Ultra-low power probabilistic IMT neurons for stochastic sampling machines

Abstract

Stochastic sampling machines (SSM) utilize neural sampling from probabilistic spiking neurons to escape local minima and prevent overfitting of training datasets [1]. This enables improved error rates compared to deterministic implementations, and, in turn, enables lower bit precision, decreased chip area, and reduced energy consumption. In this work, we experimentally demonstrate: (i) Insulator-to-Metal Phase Transition (IMT) neurons with record low peak operating power of 11.9μW at VDD=0.7V; (ii) the IMT in vanadium dioxide (VO2) provides a natural probabilistic hardware substrate for realizing a compact stochastic IMT neuron for SSMs; (iii) implementation of SSM for pattern recognition on MNIST database [2] using experimentally calibrated device modeling. These results are compared to a 22nm CMOS ASIC which shows stochastic IMT neuron based SSMs result in a 4.5x reduction in system power consumption.