Implementing p-bits With Embedded MTJ

Magnetic tunnel junctions (MTJs) utilizing unstable magnets with low barriers have been shown to be well-suited for the implementation of random number generators (RNGs). It has recently been shown that completely new applications involving optimization, inference, and invertible Boolean logic would be enabled if many RNGs can be interconnected to form large scale correlated networks. However, this requires a new device, namely, a three-terminal tunable RNG or a p-bit, whose input terminal can be used to pin its output to 0 or 1. In this letter, we show that a voltage driven p-bit can be implemented simply by incorporating existing RNGs into a transistor circuit using experimentally demonstrated 2-terminal MTJs, without requiring a new device. Using established SPICE models, we show that this proposed p-bit can be interconnected to build correlated p-circuits to implement useful functionalities including a representative example of an invertible AND gate that “factors” the output of an AND gate into consistent input combinations.