SQM: Superconducting Quantum Interference Device (SQUID)
Superconducting Quantum Interference Devices are are spectacularly sensitive magnetometers based on Josephson junctions. Applications of SQUIDS vary from "mindreading" to testing General Relativity. In this experiment, basic properties of SQUIDS will be studied and some advanced experiments done. Brian Josephson received the Nobel Prize in 1973 for his prediction of the Josephson effect.
The write-up is Mr. Squid User's Guide Write-Up Version 6.7.
(The experiment is currently located in MP239; last write-up revision: 2016.)
Additional resources and notes:
- If the above link to Version 6.7 does not work for you, click here for the almost identical Version 6.6.
- An informative 1997 article on SQUIDs from the Encyclopedia of Applied Physics.
- Mr. SQUID 44 GHz Oscillator MS-OSC User's Manual
- Mr. SQUID Flux-locked Loop MS-FLL User's Manual
- Mr. SQUID Digitizer MS-DAQ14 Brochure
- An earlier (February 2015) microwave generator used for some parts of this experiment is a Stellex 6755-722F YIG (Yttrium Iron Garnet) Oscillator with a 6.31 GHz centre frequency. The control box current shifts this frequency up or down by 5 MHz/mA.
In V-I mode, both X and Y channels on the oscilloscope must be DC coupled, otherwise you will likely have unwanted and confusing hysteresis.
The Mr. SQUID setup, with shielded dewar on floor at right.