SQUID
Definition
Superconducting Quantum Interference Device; an ultra-sensitive magnetometer exploiting quantum flux quantisation in a superconducting loop; requires cryogenic cooling but can detect magnetic fields at the femtotesla level.
- Full name
- Superconducting Quantum Interference Device
- Function
- Ultra-sensitive magnetometer
- Physical basis
- Quantum flux quantisation in a superconducting loop
- Requirement
- Cryogenic cooling
- Sensitivity
- Femtotesla-level magnetic fields
Common questions
What forensic applications rely on SQUID-level magnetic sensitivity?+
SQUID magnetometers are used in forensic geophysics to detect faint magnetic anomalies from buried metallic objects, such as weapons or clandestine graves disturbed by digging, at sensitivities ordinary handheld metal detectors cannot match.
Why does a SQUID need cryogenic cooling to function?+
Its sensing element depends on superconductivity, a state that only certain materials reach near absolute zero, so the device must be kept at cryogenic temperatures for the quantum interference effect it measures to occur at all.
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