Their approach, which they have proven to work theoretically, relies on quantum interference. (sciencedaily.com)
«Detecting small metallic contaminants in food via magnetization: A practical metallic - contaminant detecting system using three high - Tc RF superconducting quantum interference devices (SQUIDs).» (sciencedaily.com)
The white dots making up squares arrayed 45 - degrees to the x / y - axis are selenium (Se) atoms, while the defects — missing Fe atoms in the Fe plane, about a quarter of a nanometer below the Se surface — show up as butterfly - shaped perturbations produced by quantum interference of electrons scattering from the defects. (sciencedaily.com)