Nanoarchitectonics for Non‐Volatile Ternary STDP Synapse Using Anti‐Ferroelectric Carbon Nanotube Devices

Abstract Anti‐ferroelectrics (AFEs) offer unique properties such as double hysteresis window, high endurance, and low latency, making them appealing for neuromorphic computing architectures. This study introduces a novel, compact, and energy‐efficient neuromorphic circuit for spike‐timing‐dependent plasticity (STDP) synapse using AFE field‐effect transistors (AFeFETs). Although AFeFETs are volatile and unsuitable for storing synaptic weights, carbon nanotube field‐effect transistors (CNTFETs) are employed with multi‐threshold operation to achieve nonvolatility by shifting polarization‐electric field (P‐E) characteristics. By leveraging the tunable hysteresis characteristics and negative differential resistance (NDR) effect of AFeCNTFETs, a nonvolatile ternary weight storage latch is demonstrated to store STDP‐governed synaptic weights. Simulation results show that this synapse improves power efficiency by 30% and saves 93% of energy compared to previous works while remaining immune to power outages. This efficient neuromorphic building block paves the way for enhanced neuromorphic learning architectures.