APS March Meeting 2018
Volume 63, Number 1
Monday–Friday, March 5–9, 2018;
Los Angeles, California
Session L32: Physics That Changed the World
11:15 AM–2:15 PM,
Wednesday, March 7, 2018
LACC
Room: 408A
Sponsoring
Unit:
FIAP
Chair: Eli Yablonovitch, Univ of California - Berkeley
Abstract ID: BAPS.2018.MAR.L32.2
Abstract: L32.00002 : The Ubiquitous SQUID: History and Applications
11:51 AM–12:27 PM
View Presentation
Abstract
Author:
John Clarke
(University of California, Berkeley)
One-half century after the discovery of superconductivity, superconducting
electronics was born in a remarkably short time: 1961 -- 1964. The essential
steps were the observation of the quantization of magnetic flux in a
superconducting loop in units of the flux quantum, the prediction and
subsequent observation of Josephson tunneling, and the invention of the
SQUID---Superconducting QUantum Interference Device. The SQUID is an
ultrasensitive detector of changes in magnetic flux that one can configure
to measure many other physical properties, for example current, voltage,
magnetic field gradient and high frequency electromagnetic fields. SQUIDs
have a wide range of applications. A widely used commercial system enables
the automated measurement of a great variety of magnetic and other physical
properties, ranging from high temperature superconductors to blood samples.
A SQUID-based geophysical survey technique has discovered the world's
largest deposit of silver. In magnetoencephalography (MEG), helmets
containing typically 300 SQUIDs detect signals emanating from the human
brain. This technique is used in presurgical mapping of brain tumors and
locating and presurgical mapping of epileptic centers, as well as in many
research topics. Ultralow field magnetic resonance imaging (ULFMRI) at
fields comparable with the Earth's field offers high tissue contrast, for
example, in imaging tumors. The combination of MEG and ULFMRI using the same
SQUID array offers intriguing new clinical possibilities. Astronomical
telescopes containing many thousands of SQUIDs reading out superconducting
transition edge sensors---with single photon sensitivity---have made major
advances in studies of the cosmic microwave background. The Axion Dark
Matter eXperiment (ADMX), enabled by a high frequency SQUID amplifier, is
the world's most sensitive detector in the search for the axion, a candidate
particle for the cold dark matter that is the dominant form of mass in the
Universe.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2018.MAR.L32.2