"We've created an experiment where both slits can be mechanically opened and closed at will and, most importantly, combined this with the capability of detecting one electron at a time.
"It is our task to turn every stone when it comes to the most fundamental experiments that one can do. We have done exactly that with Feynman's famous thought-experiment and have been able to illustrate the key feature of quantum mechanics," continued Batelaan.
Feynman's double-slit experiment
In Feynman's double-slit thought-experiment, a specific material is randomly directed at a wall which has two small slits that can be opened and closed at will some of the material gets blocked and some passes through the slits, depending on which ones are open.
Based on the pattern that is detected beyond the wall on a backstop which is fitted with a detector one can discern whether the material coming through behaves as either a wave or particle.
When particles are fired at the wall with both slits open, they are more likely to hit the backstop in one particular area, whereas waves interfere with each other and hit the backstop at a number of different points with differing strength, creating what is known as an interference pattern.
In 1965, Feynman popularised that electrons historically thought to be particles would actually produce the pattern of a wave in the double-split experiment.
Unlike sound waves and water waves, Feynman highlighted that when electrons are fired at the wall one at a time, an interference pattern is still produced. He went on to say that this phenomenon "has in it the heart of quantum physics [but] in reality, it contains the only mystery."
|Contact: Michael Bishop|
Institute of Physics