This talk reexamines the AB effect through the framework of quantum electrodynamics (QED) to demonstrate that the locality principle is, in fact, strictly preserved [1]. By treating the AB interaction as mediated by the exchange of virtual photons within the vacuum field, we derive a gauge-invariant effective local interaction. I will discuss how this localized phase shift can be experimentally probed using an Andreev interferometer [2]. Finally, building on this QED framework, I will briefly introduce the problem of fractional spin in two-dimensional charge-flux composites, demonstrating that full QED restores strict angular momentum quantization by revealing that the conventional fractional spin is perfectly compensated by an intrinsic interaction angular momentum mediated by the vacuum field. 

[1] K. Kang, “Gauge invariance of the local phase in the Aharonov-Bohm interference: Quantum electrodynamic approach”, Europhys. Lett. 140, 46001 (2022). 

[2] K. Kang, “Proposal for locality test of the Aharonov-Bohm effect via Andreev interferometer without a loop”, J. Korean Phys. Soc. 71, 565 (2017).