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 potential, despite being confined to a region in which both the magnetic field B {\displaystyle \mathbf {B} } and electric field E {\displaystyle \mathbf {E} } are zero. Wikipedia