Little-Parks Effect — Superconducting Ring

Parameters

Temperature T / T_c0: 0.97 Ring radius R (in units of ξ): 5 Ring width d / R: 0.1

Current state: Normal

Little-Parks effect: A superconducting ring threaded by magnetic flux Φ shows oscillations in T_c with period Φ₀ = h/2e (the flux quantum). The order parameter must be single-valued, so the kinetic energy of Cooper pairs creates an effective potential that depends on n − Φ/Φ₀, where n is an integer winding number. This periodic modulation was first observed by Little and Parks in 1962.