In one minute

Caprez, Barwick and Batelaan investigate force explanations of the magnetic Aharonov–Bohm phase shift through a macroscopic electron time-of-flight experiment. Laser pulses extract electrons from a field-emission tip; the electrons pass between solenoids joined into a magnetic toroid before reaching a channelplate detector. For 40 eV electrons, they report no solenoid-current-dependent delay, with arrival-time scatter of ±0.1 ns. Changing the acceleration voltage confirms sensitivity to electromagnetic forces, while removing magnetic shielding does not change the result. They exclude force explanations producing the delay predicted by their equation, rather than measuring a phase shift and its absence of forces simultaneously.

A macroscopic test of the Aharonov-Bohm effect