Highly Contro lable Probabilistic Bits Leveraging Instability of SiOx-Based Threshold Switching Devices for Probabilistic Computing

초록

We demonstrate probabilistic bits (P-bits) with a novel Ti/SiOx/Ti stack, which is a fundamental building block for probabilistic computing. Nanoscale SiOx, devices typically exhibit threshold switching (TS) characteristics, generating reliable voltage oscillations at a given input voltage (V-in) pulse. Here, we introduce a chemically reactive Ti scavenging layer at the interface between the electrode and SiOx, to promote the instability of TS, causing variation. This leads to the random voltage oscillation with the unexpected failure to represent the data '1', enabling stochastic P-bit operation. More importantly, the SiOx, film sandwiched with Ti layers at both interfaces allows the probability of data '1' (P-1) to be precisely controlled as a function of V-in. This results in a sigmoidal Pi curve over a wide range of V-in greater than 1.4 V. Therefore, leveraging the developed SiOx-based P-bit can speed up the algorithm for finding the optimal path in the vehicle routing problem, which is verified through MATLAB simulation.

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