Superconducting circuits without inductors based on bistable Josephson junctions

Abstract

Magnetic flux quantization in superconductors allows the implementation of fast and energy-efficient digital superconducting circuits. However, the information representation in magnetic flux severely limits their functional density presenting a long-standing problem. Here we introduce a concept of superconducting digital circuits that do not utilize magnetic flux and have no inductors. We argue that neither the use of geometrical nor kinetic inductance is promising for the deep scaling of superconducting circuits. The key idea of our approach is the utilization of bistable Josephson junctions allowing the representation of information in their Josephson energy. Since the proposed circuits are composed of Josephson junctions only, they can be called all-Josephson junction (all-JJ) circuits. We present a methodology for the design of the circuits consisting of conventional and bistable junctions. We analyze the principles of the circuit functioning, ranging from simple logic cells and ending with an 8-bit parallel adder. The utilization of bistable junctions in the all-JJ circuits is promising in the aspects of simplification of schematics and the decrease of the JJ count leading to space-efficiency.

References in corpus (16)

• Coupling of two superconductors through a ferromagnet : evidence for a pi-junction
• Ultra-Low-Power Superconductor Logic
• Superconductor Digital Electronics: Scalability and Energy Efficiency Issues
• Beyond Moore's technologies: operation principles of a superconductor alternative
• Experimental evidence of a ϕ Josephson junction
• Memory cell based on a $\phi$ Josephson junction
• Pure 2nd harmonic current phase relation in Spin filter Josephson junctions
• Ground state and bias current induced rearrangement of semifluxons in 0-pi long Josephson junctions
• Second-harmonic current-phase relation in Josephson junctions with ferromagnetic barriers
• Superharmonic long-range triplet current in a diffusive Josephson junction
• Superconductor Electronics Fabrication Process with MoN${}_x$ Kinetic Inductors and Self-Shunted Josephson Junctions
• Long-Range Superharmonic Josephson Current
• Method for reliable realization of a varphi Josephson junction
• Current-phase relations in SIsFS junctions in the vicinity of 0-$\pi$ transition
• Analytical analysis of ground states on 0-$\pi$ long Josephson junctions
• Josephson $\phi$-junctions based on structures with complex normal/ferromagnet bilayer

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• Effect of 2${}^{\text{nd}}$ harmonic current--phase relation on a behavior of a Josephson Traveling Wave Parametric Amplifier
• Magnetic force microscopy versus scanning quantum-vortex microscopy: Probing pinning landscape in granular niobium films
• Large critical current density Josephson $\pi$ junctions with PdNi barriers
• Digital-analog concept for superconducting perceptron-like neural networks