Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Synaptic weighting in single flux quantum neuromorphic computing



Michael L. Schneider, Christine A. Donnelly, Ian W. Haygood, Alex Wynn, Stephen E. Russek, Manuel C. Castellanos Beltran, Paul D. Dresselhaus, Peter F. Hopkins, Matthew R. Pufall, William H. Rippard


Josephson junctions act as a natural spiking neuron-like device for neuromorphic computing. By leveraging the advances recently demonstrated in digital single flux quantum (SFQ) circuits and using recently demonstrated magnetic Josephson junction (MJJ) synaptic circuits, there is potential to make rapid progress in SFQ-based neuromorphic computing. Here we demonstrate the basic functionality of a synaptic circuit design that takes advantage of the adjustable critical current demonstrated in MJJs and implement a synaptic weighting element. The devices were fabricated with a restively shunted Nb/AlOx-Al/Nb process that did not include MJJs. Instead, the MJJ functionality was tested by making multiple circuits and varying the critical current, but not the external shunt resistance, of the oxide Josephson junction that represents the MJJ. Experimental measurements and simulations of the fabricated circuits are in good agreement.
Scientific Reports


neuromorphic, spintronics, single flux quantum, Josephson junctions, circuits, SFQ-based neuromorphic computing, MJJ functionality


Schneider, M. , Donnelly, C. , Haygood, I. , Wynn, A. , Russek, S. , Castellanos, M. , Dresselhaus, P. , Hopkins, P. , Pufall, M. and Rippard, W. (2020), Synaptic weighting in single flux quantum neuromorphic computing, Scientific Reports, [online], (Accessed June 24, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created January 22, 2020, Updated June 17, 2020