Ch 24 Live Lecture - Double-Slit Interference

In the classical double-slit experiment, a beam of light is shone onto a screen through two slits, which results in an interference pattern on the screen.

E. L. Cleveland

Rachid Nassif

The aim of the present lecture note is not to propose an alternative formulation of quantum mechanics, but to emphasize that several apparently distinct descriptions of the double-slit experiment may be understood as complementary consequences of a single geometric projection onto the transmission subspace defined by the apertures. Modeling the double slit as a projection onto the two-dimensional transmission subspace spanned by the localized slit modes provides a common mathematical framework for the wave-based, particle-based and information-theoretic descriptions of interference. The formalism starts from an arbitrary incident localized wave packet and naturally reproduces Duane's momentum-selection law, which emerges directly from the geometric transmission condition rather than being introduced as an independent postulate.

Ian MacInnes, Andrew Donaldson

What is the most beautiful experiment in physics? More than 200 readers replied when Robert Crease asked this question in May, and their top five choices include classic experiments by Galileo, Millikan, Newton and Thomas Young (see pp19–20). But uniquely among the top 10, the most beautiful experiment in physics – the double-slit interference experiment with electrons – does not have the name of an individual associated with it. Most discussions of double-slit experiments with particles refer to Feynman's quote in his 1963 lectures: "[It] is absolutely impossible to explain in any classical way and has in it the heart of quantum mechanics. In reality, it contains the only mystery." But who actually carried out the experiment? Standard reference books offer no answer to this question but a search through the literature does reveal several unsung experimental heroes.

Ralph F. Baierlein, Vacek Miglus