RF SQUID
= RF SQUID
{c}
A superconducting loop containing one <Josephson junction> and coupled inductively to a radio-frequency resonator. Its flux-dependent nonlinear inductive response changes the resonator signal. A <DC SQUID> instead uses two junctions and can turn their critical-current <interference> into a voltage modulation under bias. Inductance, junction dynamics, noise and feedback determine the practical transfer function.