SQUID magnetometry
A superconducting loop turns magnetic flux into interference of Josephson currents.
$$\Phi_0=h/(2e)$$
Physical intuition
A superconducting loop turns magnetic flux into interference of Josephson currents.
Deep dive: physical mechanism
Two junctions form a flux-dependent effective critical current; flux-locked electronics linearize the readout.
What is measured experimentally?
Measure voltage or critical-current modulation versus applied flux.
Assumptions, noise and limitations
Flux noise, hysteresis and shielding determine usable sensitivity.
Research and simulation exercise
Plot ideal SQUID critical current versus flux and add asymmetry.
Connect the ideas
Explore the chapter overview, learning path, and references.