Basic Cells for Reconfigurable Superconducting Kinemonics.

In all-Josephson-junction (all-JJ) logic, cell area is determined by the size of Josephson junctions, enabling intrinsically compact layouts. Tunable kinetic inductance offers a route to add circuit reconfigurability, pushing further scaling within the same all-JJ framework. In this work we present a set of basic cells for reconfigurable superconducting "kinemonics" that exploit tunable kinetic inductances of a multilayer nanostructure to realise multiple logic functions within a single compact circuit. We then combine these gates into a universal programmable logic cell consisting of only four reconfigurable gates supplemented by a single tunable kinetic-inductance key and demonstrate that it can realise all sixteen two-input Boolean functions, making it an analogue of a look-up table with in-hardware reconfigurability. We also discuss how the same principle can be used in superconducting neuromorphic circuits, where tunable kinetic inductance controls routing, coincidence detection, inhibition, and delay for soliton-like spikes in neuron-like elements.