Dual‐Mode Oscillations in SiO _x ‐Based Threshold Switching Devices for Unconventional Probabilistic Computing

We demonstrate a single SiO x ‐based threshold switching (TS) device for dual‐mode operation, such that full‐oscillation and probabilistic‐oscillation (p‐oscillation) can be controllably selected using the input voltage ( V in ) range of 2–6 V. This functionality relies on the TS mechanism, involving the formation and spontaneous dissolution of a weak conductive filament. By optimizing the Ar:O 2 gas flow ratio during SiO x deposition, we modulate the oxygen vacancy concentration, determining the degree of variability in filament formation. This device exhibits uniform TS characteristics under low V in ( V in ≤ 3.5 V). When an AC pulse is applied to the device, voltage spikes are periodically generated owing to charging and discharging cycles, exhibiting stable full‐voltage oscillation. These devices serve as an oscillation neuron in oscillatory neural networks to accurately recognize noisy patterns. Under high V in ( V in ≥ 3.5 V), enhanced instability of these devices induces intermittent oscillation failures, yielding p‐oscillation. The probability of these spikes follows a V in ‐controllable sigmoid distribution, effectively leveraged as a probabilistic bit to solve vehicle routing problems. We implement this p‐oscillation as a robust entropy source for a true random number generator by integrating a five‐input XOR postprocessing circuit. This architecture provides critical immunity to probability deviations and ensures that the generated random numbers pass all 15 National Institute of Standards and Technology SP 800‐22 tests, as validated via physical model‐based simulations.