  In this article we demonstrate a sense in which the one-particle quantum
mechanics (OPQM) and the classical electromagnetic four-potential arise from
quantum field theory (QFT). In addition, the classical Maxwell equations are
derived from a QFT scattering process, while both classical electromagnetic
fields and potentials serve as mathematical tools to approximate the
interactions among elementary particles described by QFT physics. Furthermore,
a plausible interpretation of the Aharonov-Bohm (AB) effect is raised within
the QFT framework. We provide a quantum treatment of the source of
electromagnetic potentials and argue that the underlying mechanism in the AB
effect can be understood via interactions among electrons described by QFT
where the interactions are mediated by virtual photons.
