Aharonov-Bohm effect

The Aharonov-Bohm effect is a quantum mechanical phenomenon by which a charged particle is affected by electromagnetic fields in regions from which the particle is excluded, proposed by Aharonov and Bohm in 1959. Such effects are predicted to arise from both magnetic fields and electric fields, but the magnetic version has been easier to observe. In general, the profound consequence of Aharonov-Bohm effects is that knowledge of the classical electromagnetic field acting locally on a particle is not sufficient to predict its quantum-mechanical behavior.

Related Topics:
Quantum mechanical - Aharonov - Bohm - 1959 - Magnetic field - Electric field

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After the 1959 paper was published, Bohm was informed that the effect had been predicted by Rory E. Siday and Werner Ehrenberg a decade earlier; Bohm and Aharonov duly cited this in their second paper (Peat, 1997, p. 192).

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The most commonly described case, sometimes called the Aharonov-Bohm solenoid effect, is when the wave function of a charged particle passing around a long solenoid experiences a phase shift as a result of the enclosed magnetic field, despite the magnetic field being zero in the region through which the particle passes. This phase shift has been observed experimentally by its effect on interference fringes. (There are also magnetic Aharonov-Bohm effects on bound energies and scattering cross sections, but this case has not been experimentally tested.) An electric Aharonov-Bohm phenomenon was also predicted, in which a charged particle is affected by regions with different electrical potentials but zero electric field, and this has also seen experimental confirmation. A separate "molecular" Aharonov-Bohm effect was proposed for nuclear motion in multiply-connected regions, but this has been argued to be essentially different, depending only on local quantities along the nuclear path.

Related Topics:
Solenoid - Phase shift - Electrical potential

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