the Aharonov-Bohm effect

The Aharonov-Bohm effect is a quantum phenomenon where charged particles, like electrons, are affected by electromagnetic potentials even when they travel through regions with no physical magnetic or electric fields. In an experiment, electrons pass around a magnetic field confined inside a tube, and their behavior changes depending on the magnetic potential inside that tube. This shows that in quantum mechanics, potentials—not just fields—can influence particles’ properties, demonstrating a fundamental difference from classical physics and highlighting the importance of electromagnetic potentials in quantum theory.