Evolving nanoscale associative memories with memristors

An associative memory is an essential building block for high-level networks for cognitive or brain-like computing. In this paper we consider the problem of designing associative memories using nano-scale memristors. Until now, memristors have been exploited solely as a synapse in neural networks. Our approach is novel because it exploits the analog, time-dependent properties of memristors, resulting in more efficient and simpler designs. We have designed two complementary evolutionary frameworks for the automated discovery of circuits. The memristor-based circuits are evaluated using ngspice. Our best circuit only uses three memristors for a fully functional associative memory of two inputs. HP has demonstrated practical memristors working at 3nm × 3nm sizes in terms of area. At these densities our associative memory could easily rival even the current sub-25 nm flash memory technology.