Theory 08/Superconductivity
Pinning Depends on Defect Spacing
The claim
The maximum pinning force is set by the ratio of vortex spacing to defect spacing, peaking when the two match rather than at maximum defect density.
01The mechanism
Pinning is efficient when each vortex sits on a defect; too few defects leave vortices free and too many leave the vortices too close to be individually pinned.
02Predictions
- P1Pinning should peak at matched spacing.
- P2Defect density alone should mispredict.
03Refutation
Pinning increasing monotonically with defect density would remove the matching condition.