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.

Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer



Joern Beyer, Dietmar Drunge, Kent D. Irwin


SQUID multiplexers can be used to read out arrays of cryogenic microcalorimeters and bolometers. Time-domain dc-SQUID multiplexer configurations use an individual first-stage dc-SQUID for each detector of an array. The biasing conditions of these first-stage SQUIDs significantly affect the performance of the SQUID multiplexer. We analyze the bias conditions of the first-stage SQUIDs in terms of the total multiplexer noise and bandwidth. We present an analysis and experimental study of the operational parameters of a first-stage dc-SQUID under varied vias conditions. This analysis includes a direct measurement of the SQUID dynamic resistance and the flux noise of the SQUID biased over the range from voltage bias to current bias. Our measurements show that a matched bias of the first-stage SQUIDs improves the system noise performance as well as the first-stage bandwidth.
Review of Scientific Instruments


microcalorimeter, multiplexer, SQUID


Beyer, J. , Drunge, D. and Irwin, K. (2004), Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer, Review of Scientific Instruments, [online], (Accessed June 17, 2024)


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

Created January 31, 2004, Updated October 12, 2021