Highly Controllable Probabilistic Bits Leveraging Instability of SiO_x-Based Threshold Switching Devices for Probabilistic Computing

We demonstrate probabilistic bits (P-bits) with a novel Ti/SiO{x}/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 (Vin) 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 ' (P1) to be precisely controlled as a function of Vin. This results in a sigmoidal P1 curve over a wide range of Vin 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.