The role of electron orbital angular momentum in the Aharonov-Bohm effect revisited

TL;DR

This paper reviews the Aharonov-Bohm effect with a focus on the electron's orbital angular momentum and introduces new insights into the role of gauge fields, addressing fundamental questions about potential reality and non-locality.

Contribution

It offers a novel interpretation of the electron orbital angular momentum in the Aharonov-Bohm effect using the physical component of the gauge field, linking it to gauge invariance and non-locality.

Findings

Pure-gauge potential outside the solenoid can carry non-zero orbital angular momentum.

Provides a new perspective on the reality of electromagnetic potentials.

Addresses gauge-invariance and non-locality in the Aharonov-Bohm effect.

Abstract

This is a brief review on the theoretical interpretation of the Aharonov-Bohm effect, which also contains our new insight into the problem. A particular emphasis is put on the unique role of electron orbital angular momentum, especially viewed from the novel concept of the physical component of the gauge field, which has been extensively discussed in the context of the nucleon spin decomposition problem as well as the photon angular momentum decomposition problem. Practically, we concentrate on the frequently discussed idealized setting of the Aharonov-Bohm effect, i.e. the interference phenomenon of the electron beam passing around the infinitely-long solenoid. One of the most puzzling observations in this Aharonov-Bohm solenoid effect is that the pure-gauge potential outside the solenoid appears to carry non-zero orbital angular momentum. Through the process of tracing its dynamical origin, we try to answer several fundamental questions of the Aharonov-Bohm effect, which includes the question about the reality of the electromagnetic potential, the gauge-invariance issue, and the non-locality interpretation, etc.