Ion Tunable Electronic Materials Systems for Neuromorphic Computing

Tuning electronic conductance through solid state electrochemical ion insertion has emerged as a promising technology to enable next-generation ultra low energy computing architectures. Unlike two-terminal non-volatile memory elements, the three-terminal redox transistor, also known as electrochemical random access memory (ECRAM), decouples the ‘write’ and ‘read’ operations using a ‘gate’ electrode to tune the conductance state through charge transfer reactions involving ion injection into the channel electrode through a solid-state electrolyte. The insertion of ions into the bulk of the channel acts to dope the material through a gradual composition modulation that leads up to thousands of finely spaced conductance levels (synaptic weights) with near-ideal analog behavior. These properties enable low-energy operation without compromising analog performance. However, the strong coupling of ionic and electronic processes sharply challenges our current understanding of solid-state electrochemical systems, particularly at decreasing dimensions and timescales relevant to computing technology. In my presentation, I will summarize the rich portfolio of challenging, exciting fundamental science questions about ion tunable electronic materials systems and how we can harness these to realize a new paradigm for low power neuromorphic computing.