Controllable and Stable Quantized Conductance States in a Pt/HfOx/ITO Memristor

Quantum-level manipulation of atomic configuration offers a excellent platform for the construction of exotic nanostructures that exhibit unusual solid-state physics and electronic properties. One particular example is the memristor, in which the elaborate evolution of atomic point contact via local ionic processes and consequent stepwise device conductance quantization enable bottom-up design of in-memory computing with greatly increased data storage density and more efficient multi-value logic algorithm. In-depth understanding on the physics of atomic reconfiguration is achieved through comprehensive consideration of the thermodynamics and kinetics of nanoionics in memristors, based on which a general protocol of constructing atomic point contact structure with desired quantized conductance is established. Through energy-driven single-atom level oxygen manipulation in the reset process of a Pt/HfOx/ITO structure, up to 32 consecutive quantized conductance states with an interval of half conductance quantum that can be sustained for over 7000 s and tuned 500 times are demonstrated for the first time, not only allowing the physical implementation of ternary logic-in-memory functions, but also providing a universal methodology for building next-generation quantum electronic devices.