JJ-Soma: Toward a Spiking Neuromorphic Processor Architecture

Neuromorphic computing and artificial neurons have been shown to improve the solution for some of the complex problems for conventional computers. We present a spiking soma Josephson junction-based soma (JJ-Soma) circuit that consists of a double-junction SQUID interfered with a resistor (threshold loop), a decaying superconductor loop cut by a resistor, which is coupled to the SQUIDlike structure. The proposed soma has three main properties: 1) ultrahigh-speed operation with minimal power consumption; 2) compatibility with standard foundry processes that allow fabrication with the available infrastructure; and 3) compatibility with conventional single flux quantum (SFQ) logic gates, which enables the design and implementation of complicated networks. Each soma circuit covers 40 µm × 80 µm area on-chip with different activation functions. The circuits are fabricated in a commercial foundry for superconductors and they have been implemented and demonstrated experimentally.