Observation of Aharonov-Bohm effect by electron holography

In this experiment, an electronand optical-holographic technique is employed with small toroidal ferromagnets each forming a magnetic-Qux closure. The holographic interferometry proves that a phase difference between two electron beams having passed through the field-free regions agrees well with the fundamental relation known as the Aharonov-Bohm effect. It is also confirmed from the same hologram that Qux leakage from the toroids does not affect the conclusion.