Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

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.

300 GHz Operation of Divider Circuits using High-Jc Nb/NbxSi1-x/Nb Josephson Junctions

Published

Author(s)

David I. Olaya, Paul D. Dresselhaus, Samuel P. Benz

Abstract

We are investigating high-current-density Josephson junctions with Nb(x)Si(1-x)-barriers in single- flux-quantum (SFQ) digital circuits to evaluate their performance at clock frequencies of hundreds of gigahertz. We fabricated static divider SFQ circuits with a- Nb(x)Si(1-x) and a-Si barriers for Jc ranging from 3.5kA/cm^2 to 85 kA/cm^2. For the lower Jc range (3.5 kA/cm^2 to 17 kA/cm^2) we used optical lithography, and for the 85 kA/cm^2 junctions we used e-beam lithography. We measured SFQ circuits with a maximum operating speed of 300 GHz by use of intrinsically shunted junctions having sub-micrometer dimensions and an 85 kA/cm^2 critical current density. These results demonstrate that silicide-barrier junctions have the potential to achieve high-speed SFQ circuits and higher density circuits because the junctions are small and don’t require external shunt resistors.
Citation
IEEE Transactions on Applied Superconductivity
Volume
25
Issue
3

Keywords

Josephson junctions, Josephson devices, Josephson logic, Niobium, Superconducting devices, Superconducting device fabrication

Citation

Olaya, D. , Dresselhaus, P. and Benz, S. (2014), 300 GHz Operation of Divider Circuits using High-Jc Nb/NbxSi1-x/Nb Josephson Junctions, IEEE Transactions on Applied Superconductivity, [online], https://doi.org/10.1109/TASC.2014.2373317 (Accessed October 1, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created December 18, 2014, Updated November 10, 2018
Was this page helpful?