Classical connection between near-field interactions and far-field radiation and the relevance to quantum photoemission

Interference in the far-field radiation pattern emitted from a classical current distribution implies near-field work between different spatial portions of the distribution. We examine this relationship and the essential role of system geometry for the case of two oscillating dipoles and for a Gaussian current distribution. This analysis offers a compelling argument as to why the radiation from a large single-electron quantum wave packet should not exhibit the same destructive interference as that associated with a comparable classical charge density. Our discussion draws attention to the ad hoc heuristics motivating the original derivation of a quantum electron's radiation profile. (C) 2013 American Association of Physics Teachers. [http://dx.doi.org/10.1119/1.4793437]