The Aharonov-Bohm Effect

See: Y. Aharonov and D. Bohm, "Significance of Electromagnetic Potentials in the Quantum Theory," Physical Review Series II, 115, 1959 pp. 485–491.

From Wikipedia:

The Aharonov–Bohm effect, sometimes called the Ehrenberg–Siday–Aharonov–Bohm effect, is a quantum mechanical phenomenon in which an electrically charged particle is affected by an electromagnetic field (E, B), despite being confined to a region in which both the magnetic field B and electric field E are zero. The underlying mechanism is the coupling of the electromagnetic potential with the complex phase of a charged particle's wavefunction, and the Aharonov–Bohm effect is accordingly illustrated by interference experiments.

Further Reading

The Early History of the Aharonov-Bohm Effect (a PDF of a paper by Basil Hiley).

The Aharonov-Bohm Effect (a PDF of a bachelor thesis by Oliver Orasch).

Aharonov-Bohm Effect (a PDF of a seminar by Ambroz Kregar).