Diffraction from static potential in QED

TL;DR

This paper models diffraction of electrons and photons from a cylindrical potential barrier in QED, comparing quantum results with classical diffraction and analyzing interference effects.

Contribution

It introduces a quantum electrodynamics approach to diffraction from a wire-like potential and compares it with classical Fraunhofer diffraction, highlighting differences in wire radius estimation.

Findings

Quantum and classical diffraction results generally agree

Classical approach overestimates wire radius

Interference effects between two beams are analyzed

Abstract

We model a wire as a cylindrical potential barrier and calculate diffraction from that potential using quantum electrodynamics. We compare our results with classical Fraunhofer diffraction. We find general agreement between the quantum and the classical results; however, we find that the classical approach overestimates the wire radius. We consider an incoming electron beam diffracting from the potential. We also consider the case of an incoming photon beam. For the photon case we only indicate the amplitudes that need to be evaluated numerically. We also study the case of two beams in phase that interfere and diffract from the wire-like potential.