By Topic

Superconducting quantum interference devices: State of the art and applications

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Kleiner, Reinhold ; Phys. Inst.-Exp.phys., Univ. Tubingen, Germany ; Koelle, Dieter ; Ludwig, F. ; Clarke, John

Superconducting quantum interference devices (SQUIDs) are sensitive detectors of magnetic flux. A SQUID consists of a superconducting loop interrupted by either one or two Josephson junctions for the RF or dc SQUID, respectively. Low transition temperature (Tc) SQUIDs are fabricated from thin films of niobium. Immersed in liquid helium at 4.2 K, their flux noise is typically 10-6Φ0 Hz-12/, where Φ0≡h/2e is the flux quantum. High-Tc SQUIDs are fabricated from thin films of YBa2Cu3O7-x, and are generally operated in liquid nitrogen at 77 K. Inductively coupled to an appropriate input circuit, SQUIDs measure a variety of physical quantities, including magnetic field, magnetic field gradient, voltage, and magnetic susceptibility. Systems are available for detecting magnetic signals from the brain, measuring the magnetic susceptibility of materials and geophysical core samples, magnetocardiography and nondestructive evaluation. SQUID "microscopes" detect magnetic nanoparticles attached to pathogens in an immunoassay technique and locate faults in semiconductor packages. A SQUID amplifier with an integrated resonant microstrip is within a factor of two of the quantum limit at 0.5 GHz and will be used in a search for axions. High-resolution magnetic resonance images are obtained at frequencies of a few kilohertz with a SQUID-based detector.

Published in:

Proceedings of the IEEE  (Volume:92 ,  Issue: 10 )